my motherboard/cpu is less than two years old (i could get exact if i had to) and the fan recently started squealing upon startup. it lasts for a few minutes before going away. it only happens if the computer is "cold" - if i turn it off and right back on a couple minutes later, nothing happens. the squeal is accompanied by horizontal lines at the top of my monitor. they both go away about the same time.

i don't remember for sure, but it may have started the same time that i purchased and installed a new agp video card.

Open the case and look at the fans as you boot up. The lines on the monitor indicate it might be the fan on your video card if there is one. Also make sure the noise isn't coming from your power supply or any other internal fan. Make sure you are grounded to the case if you touch anything but only do that if the power is off.

Try and isolate the effected part. Take the video card out of the system and replace it (for the moment) with your old card and see if the problem goes away. If it remains, BRIEFLY unplug the processor fan and power up. From your note you should be able to tell pretty quick if you find the problem. Replug the processor fan after your check! The power supply fan.... stick you ear next to it and rap the side of the supply... the pitch or intensity of the noise should change. If these things aren't making your noise... two more things I have seen. The monitor may have a bad flyback in it and will make a high pitch whine. The floppy can also go spastic and make a very wierd sound. Basically... you have a process of elimination. Good luck.

and for the record... replace a failing fan quickly. It is far cheaper than a crispy component!

Rigel

There is must be lots of dust stick on your computer fun.

unequip it carefully(don't destroy your cpu) and clean it.

if possible add some oil into the fun motor. (uncover the brand )

I think it works.

Good luck :-) if it works, tell me