Guys,

Try ATITool 0.27. It works for both ATI and Nvidia cards on Windows XP and Windows Vista 32-bit without any problems. Its an effective temperature monitoring software tool that will reside on the system bar and constant providing temperature readings. It also supports overclocking and other tweaking features on the same software. It works for my 8800GTS so your 8800GT should work also.

Give it a try.