Howto Register (copy) a dll in GAC under Server 2008 R2 w/o installing additional software

It was a pain. There is plenty of information in the web, but they do not target Server 2008 R2, or require installation of VS or .NET Framework 2.0 Software Development Kit (SDK). First let me just point out that gacutil when you run a command:

gacutil /i yourdll.dll

Will just copy a dll to GAC folder, so you can do it manually without gacutil, if you know how.

When you try to drag and drop a dll from one folder to GAC folder you receive a message 'Access is denied' (as in screen), or nothing seems to happen (depending on a configuration). To copy dll to GAC you need to turn off UAC (User Account Control - a thing that blocs you from doing something interesting under Server 2008) you need to:

Start->Control Panel->User Accounts->User Accounts->Change User Account Control settings

And set it to 'Never notify' (as in screen). You need to restart your machine.

After you restart it you will be able to grab and drop from any window to GAC folder.