Can you boot this computer into Safe Mode, and if so, does it perform well in that mode?
For Safe Mode; turn the computer on and just before the Windows logo displays start pressing the F8 key gently once a second until a list of Safe Mode options display. Select the top one, Safe Mode if not already selected, (using the arrow keys), and press Enter. XP will attempt to load with generic drivers and fewer services. The video driver will be generic VGA so your screen resolution will be the lowest, grainy and large icons.
In this mode head over to the Event Viewer, (Control Panel (in Classic Mode) > Administrative Tools > Event Viewer. Look under both the Windows System and Windows Applications for any Errors or Warning entries for the dates/times when these errors occurred. The purpose is to see if any files are mentioned, like driver files, (somefile.sys), or others.
Run both your anti-virus and MBAM scans in this Safe Mode. If MBAM needs updating you can either reboot back to normal mode to update it or reboot to Safe Mode and select "Safe Mode with networking", since this safe mode has no internet access.
Let us know how you get on.
Mark
I think my computer has a virus, and I just pulled a Trojan Sirefef.P and an Exploit: Java/ CVE 2012 0507.CG off of it today. I noticed an issue a few days ago when my screen would go black for 1-2 seconds, then come back on. Then it started freezing, making images and scattered out in lines. It would flicker and come back normal. After an hour it flickered and restarted itself. It gave me a blue screen, and when I rebooted it have me a few codes. I've run virus scans all day, but only full scans pull anything up. Malwarebytes doesn't find anything, but MSE does, which is weird, I think. I removed the viruses it found, but the issue is still there. Is this just a virus issue or is it a new hardware problem? Nothing has been updated or installed other than virus ID updates.
The codes I received after booting up from blue screen are:
BCCode: 100000ea
BCP1: 864B9808
BCP2: 864E2460
BCP3: F7A53CBC
BCP4: 00000001
OSVer: 5_1_2600
SP:3_0
Product: 256_1
Also, the model name of my computer is VGC-RB53. I think the brand name is VISO? It also says its a Pentium 4, if that helps.
PS: I'm not the most tech-savvy guy. I can run a basic virus scan and delete my history, but that's about all I can do on my own.

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