If You want to deploy your dll directly to the windows assembly

when ever you build you visual studio project

use those build events

Pre Build Events :

"C:\Program Files\Microsoft Visual Studio 8\SDK\v2.0\Bin\gacutil.exe" /u $(TargetName),Version=1.0.0.0,Culture=neutral,PublicKeyToken=7f94b68bc5abf6e5

 

Post Events

copy $(TargetPath) $(ProjectDir)gac\
"C:\Program Files\Microsoft Visual Studio 8\SDK\v2.0\Bin\gacutil.exe" /i "$(TargetPath)"
iisreset