I upgraded an XP machine to Vista Business a while back. Everything was fine, but I noticed that lately the system has been running a little hot. The laptops fan was on most of the time. Checking task manager I noticed that zcfgsvc.exe was taking up quite a bit of CPU time. I downloaded the Intel drivers for the 3945abg wifi card, and started the setup. It informed me that the current driver was meant for a previous version of windows, and asked if it should remove it. I said yes. The installation hung. I tried rebooting, the system hung on shutdown. I hit the powerbutton.
Once rebooted, this time I just went to device manager, network adaptors, 3945 card, drivers, and update drivers. This time it upgraded to the new driver, and the systems been running a lot cooler since.