I just replaced my Intel E18764-001 CPU fan with a new (used) one and verified that it is working. Now, on startup I get an American Megatrends (AMI)BIOS message that says "CPU Fan Error - Press F1 to proceed." This message was coming up before I replaced the fan. Is there something wrong with my BIOS settings? How can I determine if an update is needed?

WinXP SP3 system, Intel Core2 Duo CPU E4600 (2.4 GHz, 2.0 GB Ram, Intel G35 Express Chipset Family).