I run Vista on a homemade desktop. My CPU fan had never changed its operation in the 6 months I ran Vista until a few weeks ago. Previously my CPU fan would always come on at its highest velocity immediately after starting. After about 20 or 30 seconds it would gradually slow down, and within probably 10 seconds it would be at the appropriate level. (I have a continuously variable speed CPU fan, and I have it set pretty much in the middle.) About a month ago, it started staying at maximum velocity well after the system is booted, and 1-2 minutes after Vista is fully loaded it would then gradually come down. Other times it would start out the predetermined speed and would not be at high velocity at all during the boot sequence. And yet other times it would perform its old standard and drop velocity about 30 seconds into boot. I formatted and reinstalled Vista about a week ago because I was having some issues in addition to this and tried to format as a cure-all, but this issue remained. My assumption is that the problem may lie with the BIOS, but I have not actually rummaged around in there yet. Any ideas?
