Desktop Operating Systems and Recovery

Model #: HP Compaq Pro 6305 SFF
Product #: E6K87US#ABA
[personal information removed]
Software Build #: 12WWKCHW606#SABA#DABA
Service ID #: 20130923
PCBRAND #: HP

Hi,
I'm at a loss on what's happening to my computer. The computer is randomly restarting. When this first started happening...I honestly just thought the computer was doing updates and shrugged it off. I had went to another forum to ask for help and that got me into more of a mess than the one I was already in. Thankfully I was able to undo that mess with the system restore feature. So I really just want to focus on the restart issue. It's random. There's days the computer could be on for hours and it not happen. There's days the computer could only be on for a few minutes and it restarts. There's never any error message that pops up before or even after the computer has restarted.

I'm somebody that doesn't do a lot on this computer. I go to a few sites and it's not like I have 50 windows open at the same time. I'd say the longest time the computer is on is when it's scanning. Currently the only security program I have on the computer is Windows Security. I did have SuperAntiSpyware and ended up deleting it because I had the hope that maybe the programs being on the machine was causing a conflict. But I never see any viruses on Windows Security, nothing would show up on SuperAntiSpyware. I even temporarily downloaded Malwarebytes to see if it caught anything. Nothing. I've been trying to fix this problem on my own and I've done what others have suggested about turning off fast startup and unclicking automatic restart if there's a system failure. I've done HP diagnostics tests and nothing shows up as having anything wrong.

I downloaded a program to see if the computer was overheating and the temps look fine. Other than the random restarts, everything else seems to be working just fine. It's not like the computer is as slow as a snail or constantly freezing. I've tried using compressed air on the parts of the computer I have access to because I honestly don't see a way to open the computer up and truth be told, I'm kind of afraid to do it incase I can't get it back together.

Event Viewer isn't much help. It just lets me know the computer the system was rebooted without shutting down properly. Yeah, even I knew that one. I just don't know what else to do. And I wish I could say more but at the end of the day that's the only way to talk about the problem. The computer just randomly restarts on its own.

My uncle was here a couple of days ago and he's into computers. I mentioned the problem to him in passing and he thought that the machine's just wearing out. It's not like it's 15 years old but it's also not a year old either. I kinda want to say it's at least 7 years old.

I'm hoping somebody can help me. And if it's a worst case scenario of the computer is just wearing out, can I stretch the life of the computer by cutting down on using it? Maybe only turn it on when I truly have to? I have a kindle that I can do the light stuff on it and save the desktop use for serious stuff or when I want to type something out.

I'm sorry this is such a long post and I'm just hoping that somebody can help me with this. I appreciate it.