I initially noticed an issue with my self built computer several months ago, it was a build that was done fairly cheap and to fit my needs; gaming and the occasional reports and essays.
My specs are:
P5N-D AsusTek mobo
4gb of DDR2 333mhz Kingston RAM dual channel
Intel Core 2 Duo E7400 2.8ghz
Nvidia GeForce 9800GTX+
The issues that I am receiving that I've noticed is during boot-up it will fail to load the gui and stay at a loading screen for windows or a black screen. This will occur through several start ups and eventually succeed in a normal load up after two to three times. This also does not occur if I am shutting down and restarting immediately, only during intervals of one or more hours that the computer has been powered down.
The other issue I have noticed is decreased performance. Most noticeably if I have Firefox opened and open several tabs or windows, something I do often when searching for information or general bookmarks, it will slow down the opening of new pages progressively until the browser takes 10-20+ seconds to respond. Completely closing Firefox and making sure it is not running in task manager does not remedy this, only a complete system reboot will.
Both of these issues have occurred between two hard drives and multiple complete reinstalls of the OS
Diagnosis and remedies I have attempted:
At first I was believing that my hard drive, which was reused from an old build was failing and had bad sectors. Which I replaced because I needed more space available to me. This did not fix the problem.
I ruled out malware due to multiple harddrives and reinstalls having the persistent problem as well as no detection on Anti-virus and multiple scans.
I then made the assumption it could possibly be the RAM. I made sure that the RAM was properly connected to the mobo and it was connected properly without any build-up or gunk on the connectors.
I also ran memtest86 to see if there were any failures in the RAM itself. The full amount was detected and passed as operational after two complete tests.
The only thing left that I could see having these issues and be hardware would be my mobo or processor. I ran a torture test on my cpu with Prime95, I only ran it for about 20 minutes instead of the recommended 10hours. I figured that if there was an immediate error it would not pass as long and crash the program.
I have no clue how to properly test the mobo for any errors and do not have the extra parts or funds to rampantly start replacing everything haphazardly. I and several friends who at least know basic computer functionality and fixes haven't been able to give any light to my issue. So I'd be grateful to anyone that could give me a suggestion and testing procedure I can do to find out what exactly is causing the issues, thanks.