steps to take

Get your local computer guy to check these things in order.

1. Do you have an up-to-date Antivirus+antispyware+antirootkit package installed (McAfee IS or Total Protection, Norton IS or 360, Microsoft OneCare, and is it always up-to-date with the latest virus signatures?
   It should be at the point where it can update itself without running into problems when you are online. some people ignore this step and leave their PC's vulnerable to spyware.
2. check to see that all the fans are spinning! (cpu fan, power supply fan, front fan if you have one, back fan if you have one, motherboard fan if you have one) You have to open the case to check. The fans are the most important thing.  they should be blowing a breeze on or off of whatever they are doing.
   I can usually get replacements through search engines and electronics distributors like Newark & Digikey & Mouser or local computer shops.
   If it's the power supply, you may need to get a new $40-55 power supply. [$14 for a fan from a computer store].
3. Unplug the computer.
   Vaccuum out the CPU fins inside - it may be caked with dust clods, and that means no cooling (bad). you can probably pick off the dust clods yourself with your fingers, then vaccuum the rest out with a crevice tool to get max suction, but try not to push the clods further into the fins - got tweezers?.
   You may need to remove and put back the plastic hood/air guide over the CPU to get at the metal fins.
   Do not get any magnets near the hard drive or floppy drive or hard disk.
   You might want to clean out the floppy drive too if you can while you are at it, but it's not going to affect the performance of your CPU - it's just a good idea.
4. after cleaning the computer out, do a windows-logo-flag-key+R chkdsk /f /r Enter. on linux, use badblocks -sn -b 512 -o /tmp/oops -p 1 /dev/sda1 and fsck.
   it will say it can't and ask you if you want to run chkdsk on next restart.
   type y Enter.
   then it will go away. do windows-logo-flag-key+R shutdown -f -s Enter.
   on next boot it will repair the filesystem on your hard drive.
   this may solve some of your software problems.
5. do a memory test. you will need to burn a cd from an bootable memory tester ISO cd image for this. you will need to Enter CMOS SETUP at boot (F2? Delete? one of those keys, just look) to change the boot device order so that the cdrom is before the hard disk. you should get no errors or screen corruption.

diagnosis: you either have spyware, or it's the hardware - more specifically, the CPU, motherboard, or memory or power supply.

spyware

always have the latest antivirus+antispyware+antirootkit package installed if you are going to be on the internet or are going to be getting files from buddies via flash drives or cd's.

don't open attachments in emails (such as greeting cards) or anything that ends in .pif or .exe or .scr and be suspicious of .zip files as well. there are other executeable fiole expentions like .txt and .doc and .xls (.doc and .xls can contain malicious macros). If you are downloading or opening an attachment using yahoo mail/gmail/hotmail via the web you are probably safe, because yahoo mail (and hopefully the others) automatically scan the attachments for viruses/spyware and prevent you from downloading if it's bad. If you DO know what the attachmwent is because you know it's coming, then you should save the file and scan it before opening it. You can directly open it if your antivirus is one of those that has shields, but only if it is from someone you know and you know what it is.

sometimes you can get spyware by visiting a malicious site (albeit innocent-looking) using Internet Explorer (it might also be possible using the new Google Chrome browser, but I am unsure at this point). Another reason to have the antivirus+antispyware+antirootkit package.

• Microsoft OneCare
• McAfee Total Security (with that one you get SiteAdvisor, which warns you of sites with bad downloads on your search engines!).
• Mcafee Internet Security
• Norton 360
• Norton Internet Security

The backup solutions on these products or with cd burning programs aren't worth anything. Mcafee tries to stuff all your data onto 1 DVD. I have 32GB of data and 9GB is pictures which doesn't compress - it doesn't fit. yet somehow I ended up with 1 DVD. I think the backup solution is broken. If you need backup, get a real backup program (like Norton Save & Restore). You may have ntbackup already on your computer if you are running XP Pro or a fancy version of Vista like Home Premium or better. If you are running XP Home it is on your system restore cd or XP cd in a funny subdirectory with all the extras. No telling if the same is true of Vista basic. however, ntbackup on XP doesn't backup to cd's.

if you can't afford antivirus+antispyware software or yours isn't doing the job or you can't connect to microsoft/mfacee/symantec site

could be spyware. do a full pc scan as administrator account.
windows-logo-flag-key+R mrt Enter
do full scan and wait a few hours.
this is the windows malicious software removal tool.

it's time to do (as an administrator account, maybe you want to run CMD shell as admin)
windows-logo-flag-key+R chkdsk /f /r Enter. on linux, use badblocks -sn -b 512 -o /tmp/oops -p 1 /dev/sda1 and fsck.
Answer y Enter when it asks you whether you want to fix filesystem on reboot.
windows-logo-flag-key+R shutdown -f -s Enter to shut down the computer.
after computer turns off, turn it on again and wait an hour or two.

cd drives

this is only a side note.

• cd/DVD drives wear out, especially if they get dust in them. usually you can expect a drive to last about 5 years in a good environment. but by then, new media types have come out and your drive is no longer compatible with newer CDR and DVDR media - it becomes outdated. then you need firmware updates if you can get them, from the manufacturer's web site.

• bad/scratchy/dirty media or dirt on optics or bad drive causes corrupted software installs & data corruption when you use the drive.
• quick fix: get a cleaning disc and try that first. if it doesn't work and your cd drive is still flaky, check out these other solutions before replacing your drive. If you have dirty media, try this.

Power Supply

If the power supply is bad, your whole computer is going to go crazy. or it just won't boot. or it will make funny squealing noises. Run your computer for a while and let it "warm up". If your power supply's fan is blowing hot air, there is a problem. if it's warm, there may still be a problem. the air coming off the power supply should be cool.

proper computer placement

Don't store your computer in a "cubby hole" of a computer desk. no airflow! gets hot in there! bad for the computer or any electronics...

Don't put your computer on the floor. dirt and dust and pet hair!

put it on the desktop/tabletop surface, away from the dust.

cooling

Fans

Remember the fans I mentioned? they are often not ball-bearing fans. they are usually sleeve-bearing fans. and as a result, they don't last as long. or, if they are cheaply made, etc. usually you can't go very wrong with a ball bearing fan. they last a good while. but you still need to replace fans sometime. ball bearing fans need to be lubed once in a while (ignore the ads on that page).

a dead or slow/ailing fan will stop the cooling of youir PC. this is bad. hot CPU=flaky weird PC. Make sure all the fans are working in your PC, especially the power supply fan and the CPU fan.

If your video only has gone nuts, check the fan on your video card - many video cards come with insufficient fans, so you may need to get a beefier one.

dirt clods in the computer

shutdown and unplug your computer for this. you will probably need to disconnect everything and put it on the floor somewhere.

vaccuum your PC out every 6 months to 1 year, more often if you have a dusty house.

dust is the enemy of your PC. NEVER spray water or cleaner in or on your PC. Use a squeezed out slightly damp rag if you need to. (but not on the boards or electronic parts or connectors!) water has minerals... Do not use cleaning solutions on your cd drive's optical lens.

how to clean the inside of your desktop PC

cpu fan

make a note of the orientation of the cpu fan (which side has the label out, if it has one). If it doesn't, make note of which direction the arros point and write it down in a way you can remember later so you can put it back the same way.

cpu fan

You may need to remove and put back the plastic hood/air guide over the CPU to get at the metal fins.

unscrewing the cpu fan is only necessary if it is the kind of cpu fan that are over a bunch of cpu heatsink fins.

unscrew the cpu fan (4 screws usually). write down the orientation of the airflow arrows and which side has the label, if it has one. the label is the easiest indicator of which side is up. you can set that aside.

wipe the fan with a dust cloth. don't use detergents, a dry dust rag will do, maybe squeezed out slightly damp rag.

with tweezers if you have some, pick out the dirt clods that you can without pushing them into the fins.

get an old toothbrush and scoop out of the fins the rest of the dirt clods and gunk in the cpu fins. you might not be abl to get it all, but a perfect job is not absolutely necessary. just get what you can without pushing more junk into the fins.

if you can, use a crevice tool on your vaccuum to vaccuum out the cpu fins.

put the cpu fan back on the way you wrote it down.

screw the cpu fan back in. don't use a lot of force - it's bad for the cpu. be as gentle as possible.

floppy drive

dirt clods can really get in there.

if you can do a through job of cleaning out the floppy drive, all the better. I sometimes take the drive top off to do it, but you don't have to go to that extreme.

you can put your finger in the drive door and use the vaccuum crevice tool in the front, and all around it.

get a floppy drive cleaning kit and use it. they still exist.

inside the case

dust bunnies get all around inside the case.

PSU/Power Supply Unit

this thing gets a lot of crud all around it.

vaccum the vents with a crevice tool or whatever has the most suction and do the same for your fan in the back and the bottom fan if you have one.

case fans

clean the crud off of them if you can, and the dirt clods. there is possibly a case fan in the front, and a case fan at the top, side, and maybe 2 in the back, depending on your case.

laptops:

take your laptop to a laptop specialist for your manufacture of laptop.

sometimes they can get cat or pet hair in the cpu fan and the fan stops, heating the cpu up until it's burning hot. If you have a cat, you may want to mention that fact to them and to check the cpu fan for pet hair or dirt (if they are interested), and to do whatever else is necessary to fix the machine.

hot room

computers like to be cool. at least make them as comfortable as you are (room temp). If it's getting to be 80°F(26.6°C) or more, it might be time to turn the computer off until things get cooler.

laptop - no cooler?

all paptops these days should have a laptop/notebook cooler. they are about $50 max, and buying one will prevent your laptop from dying or having a short lifespan.

PSU (Power Supply) Weirdness

read my article