Hello all! A Co-worker let me borrow his Desktop PC to see why it would cut off shortly after it was turned on. Well after I replaced the power supply, his problem was fixed but I noticed it was running very slowly so I booted it up in Safe Mode to see if I could help it. Well even in safe mode it is running very slowly and making a double clicking noise every few seconds. After awhile the noise will stop and the PC will run pretty smooth but once you try to do a few things (like browsing the internet or scanning with something) it will start clicking again ad become very slow again. It's a older HP Desktop PC running windows Vista, Dual Core with 3 Gigs of Ram. On a side note the old power supply was a 200 watt and the new one is a 550 watt. I also caught a few viruses/spyware/PUPs but nothing real bad and I cleaned it up with CCleaner. Any ideas to what could be causing the clicking? Sounds like it's coming from the HDD but not 100% sure on that.