how to unregister/remove dll files in windows xp or vista
1. Open the Command Prompt window
Go to start on your taskbar and click on “Run” to start the “Run” tool. In the field, type “cmd” and press the “OK” button.
Windows Vista doesn't have run in start menu, pressing "windows"+"R" to access it.
2. Unregister the unwanted DLL
Type “regsvr32 /u DLL_FILENAME” and press the “Enter” button.
"DLL_FILENAME" is the name of dll you want to unregister.
Now you can delete the unregister malicious dll file.
If you unregister the system DLL file, your computer may crash and important data in your computer may be lost. Please make a backup first!