1. You turn the PC on, it loads through and then reports it cannot find the C Drive
This sounds like a fault hard disk, swap it with another from a working PC, if the problem resolves this way then your drive is bad.
The hard drive is found inside the case, it will have a ribbon attached to the mainboard and one of the power leads from the PSU. It is fixed with screws into the case, undo these, whip out the cables and get yourself a new disk.
Sometimes a reboot will give your disk a little more life, if a reboot does help, then make sure you backup your data straight away and get a new disk in there! This is a best case scenario, normally if the C Drive dies you lose all your data, if you can save it this way then you were lucky!
2. No activity when turning the computer on
You hear nothing, no lights start frantically flashing at you, nothing appears on the screen? First things first, check that it is plugged in!!!
Okay enough of the sillyness, the thing is plugged in, it now seems like the PSU (Power Supply Unit) has died a horrible death! The PSU is a box normally at the back of your computer held into the case by 4 screws and has a fan blowing bad air out of the back! There is also a wiring loom that comes from this dreaded box into the main board of the pc. It is this wire that feeds electricity to all of the components inside your PC! Unplug all these power wires and unscrew the PSU, you can now take it to the PC Store and show the guys there, they will then get you a new one!
3. Regular Blue Screen Errors, sounds like a memory problem to me!
You are using your PC, happily writing documents or surfing the Internet, when BAM, Blue Screen of Death is telling you there was a fatal error and your computer needs to be put into the retirement home. Fear not, 9 out of 10 times this is just unfortunate and unavoidable, but a restart will cure it. However, if you keep getting this regularly then you may have a RAM (Random Access Memory) problem. This is again easily fixable using other memory sticks. If you have a PC that works fine, try swapping the memory sticks to see if this remedies your problem. You can get memory testers that can tell you if your RAM is bad, try running one of these. If you do end up with a bad RAM stick, then nip down to the store and buy a new one!
RAM sticks fit into the main board normally not far from the processor. Just flip the little switches at either and and pull the old one out, line up the new one with the slots and push down. Once you hear a click at both ends, you’re ready to go!
4. The computer starts up, but the monitor is blacker than the black hole of calcutta!
Basically this means your monitor has had it. Again check it is plugged in etc. If you have a different monitor lying around you can use, try plugging that in. If it works then it’s a safe bet the first one is ready for the scrap heap. Monitors store electricity inside them using capacitors, don’t every try to repair one!!! This stored electricity has the potential to kill you!!!
If the monitor does come on (Power Light is shining bright) but the screen is black, then it could be a Video Card problem. Firstly identify the Video Card in your PC, should be pretty easy, it has the monitor plugged into it. If it is part of the main board then you can’t do much about it buster, however if it is separate be sure it is firmly pushed into it’s little slot, if this does no good, then remove the card and get yourself a new one. They are fairly inexpensive unless you are a serious gamer, then you could be looking at the hundreds and thousands!