Okay so I am having this weird problem with my computer, I'm pretty sure it's the power supply but not 100% certain

My computer works fine, except the last 2 days it's turned itself off 3 times, the last time it happened it wouldn't turn back on, so I left it alone and tried one more time, and that time it turned on. So..... I dunno? I think the power supply might be going, or my system is overheating, what do you think?

It could be that your processor is overheating and your BIOS is set to shut down at a certain temperature. I just had some trouble of my own with a power supply, where my computer would light up, fans spin, but the hard drives wouldnt. Soon after replacing PSU, everything works fine. Check your BIOS for a max temp, and maybe increase it if it is a bit low. Also, check your event viewer (Start>control Panel> Administrative tools> Event Viewer) and see if you are getting "Bug Checks" or "Unexpected Shutdown" in the "System" area of the Event Viewer and post back

I have a few weird ones:

The process winlogon.exe has initiated the restart of JESSICA for the following reason: No title for this reason could be found
Minor Reason: 0xff
Shutdown Type: reboot
Comment:

and

TCP/IP has reached the security limit imposed on the number of concurrent TCP connect attempts.

these are from the day that it kept acting up

Event

In the event viewed, could you please list EVENT ID and the SOURCE
Along with any codes that look like 0x0000008a or similar

Dirty cpu fan, dirty power supply, heavily corrupted operating system, bad install of AOL or MSN, conflicts between drivers from Service Pack 1 and 2, along with the install of Internet Explorer 7.0... without the needed driver updates from the manufacturer, spyware... lots of things will cause it... and despite the claims of some on this forum, the power supply is usually not part of the problem unless the computer is used in intensive activity such as gaming and image editing.

well I do use it for gaming and video/image editing alot, actually that's the main things I use it for and I think it was the power supply cause I switched it, and it's been good since, and I also think the fan died on the old power supply, because it was way hotter then it should be when it failed again, so I switched it.

get a new power supply.