If nothing from previous troubleshooting articles helped to get Windows into proper working condition, there is a way to repair Windows Vista or 7 without losing all your data, documents, settings and installed programs and drivers. This type of reinstallation is also called repair install or in-place upgrade.
Options to try before repair installing Windows Vista or 7
- Last Known Good Configuration often solves booting and stability problems after installing or updating software, drivers, or messing with Registry entries.
- Always try booting into Safe Mode at least once - this often repairs corrupted file system and essential system files.
- If Windows starts and runs properly only in Safe Mode, turn on Clean Boot mode to see if some non-Microsoft software or driver is causing the problems.
- While Windows is running, use free WhoCrashed for determining BSOD (Blue Screen Of Death) causes.
Also, Reliability Monitor might reveal faulty drivers or software. - If Windows is able to boot, use System File Checker and icacls.exe to repair corrupted system files.
- Use Windows Update troubleshooter if your PC is unable to apply updates, or offers them repeatedly. If your computer crashes with error 0xc000021a right after installing latest updates, you need to run disk check to fix file system problems.
- System Restore can help reverting back to a state when your computer was running normally.
- Repair your computer is useful for fixing startup problems and file system errors, and testing memory modules for defects.
Non-destructive reinstallation requirements in Windows Vista and 7
- Windows must be running in normal mode (not in Safe Mode) and you must have administrative rights. Booting from installation DVD will not perfrom the non-destructive install.
If your computer is unable to start Windows normally, boot into Safe Mode and use it to enable Clean Boot mode. If Windows runs flawlessly in Clean Boot mode, then some third-party software or driver is causing the stability problems.
In case this method fails, follow instructions in the Recover files using Puppy Linux article. After recovering files, you must reinstall Windows Vista or 7, drivers and programs, and then copy your documents from the backup media you used earlier. This is the hard way in case Windows Vista or 7 does not start at all. - Windows installation or upgrade media (DVD). Manufacturers' Recovery DVD-s will not help here - they delete and reinstall everything! Custom slipstreamed DVD-s (for example, created with vLite) often cause errors, so please do not use these. Also, OEM media (the customized Windows install DVD that came with your PC) might cause errors, such as "Windows 7 Professional cannot be upgraded to Windows 7 Professional".
- Windows Product Key (aka Licence Key) is a must. This has to be the same key that was used to install the Windows you are reinstalling.
If you bought Windows Vista or 7 from a shop, the sticker is somewhere in the retail box or jewel case.
For online purchases, find the e-mail with your Windows Product Key.
In case Windows came preinstalled on your computer, look for the key sticker on the side or top of desktop case, or on the back of laptop case. For some laptops (several Dells, for example), you need to remove battery to see the sticker.
If you cannot find your product key, use free version of The Magical Jelly Bean Keyfinder.
More modern devices have encrypted product key stored inside UEFI/BIOS or TPM. In such case, download the latest version ofRWEverything. Make sure you download the correct edition: 32-bit or 64-bit. In most cases, RWPortableV<version number>.zipworks fine, you do not need the installer. After downloading, unzip the files by right-clicking on the .zip file and selecting Extract all(see more detailed instructions for compressed folders). Then navigate to the folder where you extracted the files, right-click Rw.exe and select Run as administrator. Open ACPI from the top toolbar and then open MSDM tab. The last line reveals your product key. If the MSDM tab is not available, the product key is not stored in BIOS/UEFI/TPM. - In case your installation media does not include the currently installed Windows Vista or 7 Service Pack, you might need to uninstall the Service Pack first by opening Control Panel, clicking Uninstall a program (in Category view) or Programs and Features(in Icons view), selecting View installed updates on the left and uninstalling an item named Windows Service Pack.
- Windows Vista requires at least 15 gigabytes (GB) of available disk space on system drive (drive C:, or the drive where Windows is installed).
Windows 7 needs at least 16 GB of free disk space for 32-bit (x86) editions, or 20 gigabytes for 64-bit (x64) editions.
You can see the Free up disk space and Remove temporary and duplicate files with CCleaner articles for guidance on gaining more disk space on your PC.
Also, temporarily moving your documents, photos, videos and other personal files to another drive significantly reduces the time required for the non-destructive reinstallation to complete. - If you can download the correct ISO file, a blank DVD is required for Windows installation media. The media will be formatted and all data on it will be lost. You've been warned.
- If you want to be 100% (or even more) sure that you will lose nothing important, create a full backup of your PC with free version ofAOMEI Backupper before continuing. While there is very little possibility of complete and unrecoverable failure during the repair install, you might require some extra assurance.
Downloading Windows installation media (only if you're lucky enough)
Non-OEM (if Windows was not preinstalled) users can visit the Microsoft Software Recovery page and download the Windows installation ISO by entering correct product key. This seems to work for Windows 7 only.
If you want a DVD instead of ISO (for a small fee), contact your local Microsoft support. Seehttp://support2.microsoft.com/common/international.aspx for contact information.
OEM license owners can get further help from the http://support.microsoft.com/kb/326246 page.
Burn the downloaded ISO file to a blank DVD using CDBurnerXP. If you do not have the program installed, instructions are available in this article.
To put Windows 7 (not Vista!) installation media onto a bootable USB drive instead, see the Create bootable Windows installation media on a USB stick guide on my other site, www.winhelp.info. Please connect the drive to a USB 2.0 port instead of a USB 3.0 (aka SS or SuperSpeed) or newer port. There is no native USB 3 support in Windows 7, so USB 3 or newer might cause the installation to fail.
What will change after this reinstall?
While you will not lose any documents, e-mails, settings, drivers or additional programs installed, the reinstall will revert Windows Vista or 7 to the Service Pack version on your original installation DVD. If your DVD includes no Service Pack at all, you will have no Service Pack installed.
Also, Internet Explorer will revert to version 7 in Windows Vista, and version 8 in Windows 7.
Also, Internet Explorer will revert to version 7 in Windows Vista, and version 8 in Windows 7.
It means that you will have to reinstall the latest Service Pack, newer version of Internet Explorer and all security updates. You will not lose any settings of Internet Explorer, though.
Speeding up the non-destructive reinstallation of Windows Vista or 7
Before starting the repair install, please follow these steps to speed the process up considerably:
- Move your personal files (documents, photos, videos, etc) to an external drive or to another internal drive.
- Run RKill to stop possible malware processes. Without restarting your device, install Malwarebytes Anti-Malware and run a full scanwith it. This is a must!
- Install CCleaner and remove temporary files. This is a must! At least 15 GB (gigabytes) of free space is required to reinstall Windows Vista, and at least 20 GB of available disk space is required to reinstall Windows 7.
- Run a disk check to verify that file system is intact. This is a must!
- Disable or uninstall anti-virus and anti-malware software temporarily; enable or re-install them after Windows reinstallation completes. This might help sometimes.
- Disconnect all external devices (printer, external hard drives, USB sticks, etc) that are not required during the non-destructive re-installation. Display, keyboard and mouse are required.
- Quick defragmentation with Defraggler also helps. This step is not necessary if Windows is installed on a SSD.
If non-destructive reinstallation still fails, start it in Clean Boot mode in order to make sure that no third-party software prevents the in-place upgrade from succeeding. After the process is complete, disable Clean Boot mode again.
Reinstalling Windows Vista or 7 non-destructively
The process is very similar in Windows Vista and 7, so most screenshots are from an in-place upgrade of the latter.
First, insert your Windows DVD while holding down SHIFT key on your keyboard. This will prevent AutoPlay/AutoRun from launching the Windows setup program on DVD automatically.
There is a big catch in non-destructive reinstall of Windows 7. Many users have faced a failure notice during compatibility check saying: "Your current version of Windows is more recent than the version you are trying to upgrade to. Windows cannot complete the upgrade."
To prevent this message from appearing, open the Windows 7 DVD in Windows Explorer, right-click setup.exe and choose Properties.
Click Compatibility tab on top. Click to check the Run this program in compatibility mode for: box and selectWindows Vista (Service Pack 2) from the list. The original Windows Vista without any Service Packs and any earlier Windows version (XP, 2000, NT) do not support upgrading to Windows 7 (and upgrading is what we will be doing here).
Click OK to close the setup.exe Properties window. Then double-click the same setup.exe file to launch it.
In case the compatibility check still fails, uninstall Windows 7 Service Pack as instructed in the beginning of the current article.
Install Windows window will appear. Click Install now.
In the next dialog - Get important updates for installation - click Go online to get the latest updates for installation (recommended). About 886 kilobytes will be downloaded in case of Windows Vista, and 1100 kilobytes (1,1 megabytes) in case of Windows 7.
Compatibility Check will run next. If you get errors such as "Windows 7 Professional cannot be upgraded to Windows 7 Professional" while using the install media that came with your PC (aka OEM media), you need to find an official, unmodified Windows 7 DVD or ISO image.
In case you are already using official media and the "Windows 7 Professional cannot be upgraded to Windows 7 Professional" error still appears, repair Windows Update with Fix it Tool 50202. Make sure you tick the Run aggressive options (not recommended)check box. Restart your computer after this is complete.
Then run System File Checker at least twice. If necessary, also run icacls.exe to fix system file permissions as instructed.
Then run System File Checker at least twice. If necessary, also run icacls.exe to fix system file permissions as instructed.
The last workaround for the "Windows 7 cannot be upgraded to Windows 7" error is to skip updating the installation files (choose Do not get the latest updates for installation).
In Windows Vista, you need to insert the correct Product Key. Leave the Automatically activate Windows when I'm online check box ticked.
Click I accept the license terms and then click Next.
In Which type of installation do you want? dialog click Upgrade. This will preserve all your documents, settings and installed programs while reinstalling Windows Vista or 7.
If no problems are detected during the Compatibility Check, upgrade of Windows will start. This will usually take an hour or more and several automatic restarts. There is no sense in staring at the screen during the repair installation of Windows Vista or 7, so go do something else instead. 
Please note that the installation process almost always stops at some step or percentage for a prolonged period of time (up to several hours, depending on the amount of data to process) - do not interrupt or cancel the installation!
Please note that the installation process almost always stops at some step or percentage for a prolonged period of time (up to several hours, depending on the amount of data to process) - do not interrupt or cancel the installation!
In Windows 7, the Setup is preparing your computer for first use screen means that the non-destructive reinstall is almost complete.
Windows 7 requires the correct Product Key before completion. Enter the letters and numbers and click Next. Leave theAutomatically activate Windows when I'm online box checked.
If you encounter problems activating Windows Vista or 7, call your local Microsoft support line and they will be happy to provide you with a new key after you tell that you had to reinstall your genuine copy of Windows. Remember, this works for owners of genuine (non-pirated) copies of Windows only!
In the next screen - Help protect your computer and improve Windows automatically - click Use recommended settings. This will enable Automatic Updates in Windows Vista and 7.
In Review your time and date settings, previous settings are recovered automatically, so just click Next. In the picture below are settings for Estonia, so "märts" means "March" (the month) here.
In Select your computer's current location, select the correct network type. If you are directly connected to the Internet via some modem, router or dial-up and you have no home network sharing printers or files with other computers, click Public network here. If you do share files or printers with other computers at your home, click Home network instead.
And after this, familiar Welcome Screen will appear. It will take a few minutes until all settings are applied. Just stand by.
In Windows 7, you might encounter a Microsoft .NET Framework repair message. The repair can take around ten minutes and it requires a reboot. Let it finish and then click Restart now. It is very likely that Windows has applied some critical updates during the time already.
Now your Windows Vista or 7 non-destructive re-installation part is finished.
But do not stop here yet! You still need to update Windows Vista or 7 to the latest Service Pack and install all other updates.
The next very important steps are:
The next very important steps are:
- Configure Windows Update.
- Install Service Packs in Windows Vista and 7.
- In Windows Vista, install and configure free AOMEI Backupper.
- Configure automatic backups in Windows 7.
Also, install free security software to be on the safe side:
- Free anti-virus programs
- Free anti-malware programs
- WOT Safe Surfing Tool
- Secunia PSI
- Microsoft EMET
Cleaning up after reinstalling Windows Vista or 7
Those who like to keep an eye on disk space usage will probably notice that the amount of available space on system drive C: has decreased by several gigabytes after the repair install completes or fails. This is because the in-place upgrade process stores a backup of old important system files in case something is not moved to the repaired installation properly.
Please wait at least for three days before you clean these files up - this makes sure that everything runs correctly and all files are where they should be.
If everything seems fine, open Windows Explorer (keyboard shortcut WINDOWS KEY+E), right-click drive C: (the one that has Windows icon) and select Properties. Click the Disk Cleanup button in General tab.
Windows Vista will ask whether you want to clean up just your own files or files of all users on the computer. Click Files from all users on this computer.
Wait until the first analysis completes, then click Clean up system files in the bottom left of the Disk Clean-up for (C:) window.
Scroll down the list, enable the Files discarded by Windows upgrade option and click OK.
Click Delete files to verify that you know what you are doing. The cleanup might take several minutes to complete, and the window will close automatically.
