PC suddenly lagging, even after clean install

Now it's booting fine, one beep like normal. I'll run the test just to be sure.

It seems very intermittent whether it wants to start up or not. Now there is just one long beep and then it sometimes shuts down or sometimes even the BIOS and initialisation screens are lagging/slow.

I'll keep trying to start it up.

It just shut down during the first 5 minutes of memtest. I don't know what to do...

EDIT: After running memtest again, I noticed the CPU temp was at 100 degrees. I checked on Speedfan and it is hovering around 80-90 degrees with no programs running. I'm going to try cleaning out the heatsink.

While you have it open and cleaning out the heatsink, clean everything else also.

COMPUTIAC said:

While you have it open and cleaning out the heatsink, clean everything else also.

Problem is I don't have any compressed air, but I can use a vacuum for the detached heatsink.

Do your best to clean everything you can.
Check the cooling fan's also, maybe you can wipe them with you finger to get the most off.

If you have Q-tip's they can help you also.

If the vacuum is strong enough, use it in reverse to blow out thing's.

COMPUTIAC said:

Do your best to clean everything you can.
Check the cooling fan's also, maybe you can wipe them with you finger to get the most off.

If you have Q-tip's they can help you also.

If the vacuum is strong enough, use it in reverse to blow out thing's.

Thanks for the advice. I cleaned out the CPU heatsink and reapplied the thermal paste; temperatures while idle are around 25-30 degrees rather than high 80s. So far no lag while using the PC, it seems that was the cause of the lag and random shut downs.

Resentic said:

Thanks for the advice. I cleaned out the CPU heatsink and reapplied the thermal paste; temperatures while idle are around 25-30 degrees rather than high 80s. So far no lag while using the PC, it seems that was the cause of the lag and random shut downs.

Great new's.
Keep an eye on everything and post back if anything else act's strange.

Have you tried to restart it a couple of time's to see how it act's and what beep's it make's now ?

COMPUTIAC said:

Great new's.
Keep an eye on everything and post back if anything else act's strange.

Have you tried to restart it a couple of time's to see how it act's and what beep's it make's now ?

It's much more stable; I've restarted it a couple of times, one short beep like normal and no more lag!

I want to thank axe0 for guiding me through all the troubleshooting and trying to help me resolve this :)