Здравствуйте, Аноним, Вы писали:

А>Заранее благодарю за ответ!

Когда-то наткнулся на msdn:

Reading a Registry Key

You can look for a specified registry key value to detect whether the .NET Framework is installed on a computer. The following table lists the registry keys and values that you can test to determine whether specific versions of the .NET Framework are installed.

3.0 HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.0\Setup InstallSuccess (DWORD value = 1)
2.0 HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v2.0.50727 Install (DWORD value = 1)
1.1 HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v1.1.4322 Install (DWORD value = 1)
1.0 HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\policy\v1.0 Install (DWORD value = 1)

[http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnlong/html/netfx30.asp]