Click a Nerd | .NET Cleanup Procedure

Steps to clean up a machine to fix a failed .NET Framework 2.0 installation:

Using Add or Remove Programs, locate any versions of the .NET Framework 1.2 or 2.0 and choose Remove to uninstall them
Using regedit, navigate to HKLM\Software\Microsoft\.NET Framework and delete any keys and values that have 1.2 or 2.0 in it, including keys/values that are in sub keys underneath .NET Framework.
Using regedit, navigate to the sub-hive HKLM\Software\Microsoft\.NET Framework\Policy and delete any key or value that has 1.2 or 2.0 in it.
Using regedit, navigate to HKLM\Software\Microsoft\ASP.NET and delete any key or value that has 1.2 or 2.0 in it, including keys/values that are in sub keys underneath ASP.NET.
Right-click on My Computer and choose Manage. Expand Computer Management (Local), then Local Users and Groups, then click on the Users folder. In the right-hand pane, right-click on the ASPNET user account and choose Delete to remove it.
Go to %windir%\assembly and delete anything with *1.2* or *2.0* in the folder name. Delete the GAC_32 and GAC_MSIL folders as well.

You can not view the contents of %windir%\assembly in Windows Explorer when the .NET Framework is installed. In order to view the contents, you will need to set the following registry value and reopen Windows Explorer

Key name: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Fusion
Value name: DisableCacheViewer
Data type: REG_DWORD
Value data: 1

Note: You should remove the DisableCacheViewer value after you complete this step because this is only used for debugging purposes.
Go to %windir%\Microsoft.NET\Framework and delete any folders named v1.2.* or v2.0.* along with all of the files and subfolders they contain. You may get errors when trying to delete some of the files because they are in use. In most cases, rebooting the machine and trying again will work. If not, you can rename the files to be <filename>.old and then delete them after a future reboot.
Rename %windir%\system32\mscoree.dll to mscoree.dll.old.
After doing all of this, try to install the previously failing version of the .NET Framework 2.0.


	.NET Cleanup Procedure Steps to clean up a machine to fix a failed .NET Framework 2.0 installation: Using Add or Remove Programs, locate any versions of the .NET Framework 1.2 or 2.0 and choose Remove to uninstall them Using regedit, navigate to HKLM\Software\Microsoft\.NET Framework and delete any keys and values that have 1.2 or 2.0 in it, including keys/values that are in sub keys underneath .NET Framework. Using regedit, navigate to the sub-hive HKLM\Software\Microsoft\.NET Framework\Policy and delete any key or value that has 1.2 or 2.0 in it. Using regedit, navigate to HKLM\Software\Microsoft\ASP.NET and delete any key or value that has 1.2 or 2.0 in it, including keys/values that are in sub keys underneath ASP.NET. Right-click on My Computer and choose Manage. Expand Computer Management (Local), then Local Users and Groups, then click on the Users folder. In the right-hand pane, right-click on the ASPNET user account and choose Delete to remove it. Go to %windir%\assembly and delete anything with 1.2 or 2.0 in the folder name. Delete the GAC_32 and GAC_MSIL folders as well. You can not view the contents of %windir%\assembly in Windows Explorer when the .NET Framework is installed. In order to view the contents, you will need to set the following registry value and reopen Windows Explorer Key name: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Fusion Value name: DisableCacheViewer Data type: REG_DWORD Value data: 1 Note: You should remove the DisableCacheViewer value after you complete this step because this is only used for debugging purposes. Go to %windir%\Microsoft.NET\Framework and delete any folders named v1.2.* or v2.0.* along with all of the files and subfolders they contain. You may get errors when trying to delete some of the files because they are in use. In most cases, rebooting the machine and trying again will work. If not, you can rename the files to be <filename>.old and then delete them after a future reboot. Rename %windir%\system32\mscoree.dll to mscoree.dll.old. After doing all of this, try to install the previously failing version of the .NET Framework 2.0.