Unknown Hardware Problem - System Locks Up

[boweasel]

I assume it's a hardware error because nothing ever shows up in Event Viewer.

Sometimes when I turn the PC on it boots normally and I can use for usually only a short period of time before it locks up - no response from any keys or mouse, not even cntl/alt/del. Other times the monitor stays dark and I hear what sounds like a fan noise becoming increasingly louder and louder. In both cases I have to hold in the power button to reboot.

Sometimes after it boots correctly, simply letting it sit on the desktop will cause it to freeze. I have gotten it to run a chkdsk at boot - it found no errors, as well as a complete MalwareBytes scan - no errors there either.

I have unplugged and replugged the hard drive and its connections to the motherboard. The fans on the inside of the chassis are working

To make matters worse, I thought it might be a memory problem, so I removed a stick and it began to boot, but then I got the 'The amount of system memory has changed. Strike the F1 key to continue, F2 to run the setup utility'. This PC does not have serial ports for the mouse or keyboard - only USB; and the keyboard is non-functional at this stage of the boot process.

I even put the memory back, and am still getting the memory change message.

I really don't know how to get past that.

 

[ickymay]

I assume it's a hardware error because nothing ever shows up in Event Viewer.

Sometimes when I turn the PC on it boots normally and I can use for usually only a short period of time before it locks up - no response from any keys or mouse, not even cntl/alt/del. Other times the monitor stays dark and I hear what sounds like a fan noise becoming increasingly louder and louder. In both cases I have to hold in the power button to reboot.

Sometimes after it boots correctly, simply letting it sit on the desktop will cause it to freeze. I have gotten it to run a chkdsk at boot - it found no errors, as well as a complete MalwareBytes scan - no errors there either.

I have unplugged and replugged the hard drive and its connections to the motherboard. The fans on the inside of the chassis are working

To make matters worse, I thought it might be a memory problem, so I removed a stick and it began to boot, but then I got the 'The amount of system memory has changed. Strike the F1 key to continue, F2 to run the setup utility'. This PC does not have serial ports for the mouse or keyboard - only USB; and the keyboard is non-functional at this stage of the boot process.

I even put the memory back, and am still getting the memory change message.

I really don't know how to get past that.

run the F2 to run the setup utility then exit and save your bios changes and it should boot normally

Lack of clues to help with your freeze problem , I suggest you fill out your system specs and some history ?

 

[boweasel]

Actually, this last time I got it to boot normally I did find something in the Event Viewer under Application.

This is the message I found (it was not there on any of the previous freezes):
The description for Event ID ( 1001 ) in Source ( Microsoft Security Client ) cannot be found. The local computer may not have the necessary registry information or message DLL files to display messages from a remote computer. You may be able to use the /AUXSOURCE= flag to retrieve this description

I uninstalled Security Essentials, ran CCleaner on the registry, installed Avast, and everything seems to be okay, although I don't have a clue what the message was trying to tell me and how it relates to the system locking up.