Until the last month or so, my computer has been freezing and just randomly the mouse and keyboard would not work, while the computer was still running. When I restarted the computer, the problem still persisted... I would leave it off and after a couple hours it would work.These problems only occured in games.
Though that stopped happening about a month ago, but now I have a ton of lag in all games. It isn't performing close to what it used to. I have run spyware and virus scans, and came up with nothing... Fans are all on...
this system sounds like a combination of old parts made into a new system with an expensive system - what brand motherboard do you have? and is that socket754? remove any non matching sticks of ram (or use one) and see what that does.
This sounds like a powersupply issue. Probably a component is close to failure and causing shorts, or has failed and is causing brownouts in your system. I would check it out and possibly test with another PS.
Right, as I had mentioned in the other thread, you need to pull out those sticks of RAM, and test the machine. Pull out the 2 256 chips and leave one of the 512s on the board. Test the machine's operation and run memtest. If you have a dual channel system and something is failing in the machine, chances are, your RAM is the first to become problematic. You have different RAM sizes on that board as it is which IMO, is not good and can cause instability.
Remove the RAM sticks, clean out the machine like I mentioned, make sure the inside is all cleaned out especially the fans.
I understand things were working fine before however, something went South in that machine and its obviously still not right. The only way to find out is trial and error.
If running windows XP, restore points are established. You can restore back to a time prior to where your system made a change. (Remember, if you restore, you loose all data since the restore date.) This may help in determining what happened.
If you mouse and keyboard were locking up, there must have been something out of sync prior to looseing performance.
Does the mouse lockup still occur after loosing performance?
Some motherboards will have problems with mismatched memory and/or defaulty power supply. Power may work intermittently from power surges and this would effect memory and the whole system.
Luminaris is on the right track, but I would like to add something.
It might be a wild goose chase, but while you're following Luminaris' instructions, take a flashlight and examine the capacitors on the mobo. If any of them are leaking or corroded that is most certainly your problem. Again, this might be unecessary but it would only take a minute to look at them.
If you find any you might be able to RMA the board through the manufacturer. Or, if you have access to some good desoldering and soldering equipment, you could get new ones through Digikey and replace them yourself. Or scrap it and get a new one.
I'm sure we all remember the fiasco of the bad capacitors from a few manufacturers (MSI was one of them) back in the Socket A days a few years ago. I'm not saying that is the case here, but it takes little effort to examine them. One of the old boards I had lying around had the capacitor problem but it was too old to RMA. $9.00 on some new capacitors and a hour of soldering later I had a perfect board for a charity PC I was building.