Xen from the chat room here. Just thought I should give the community my top five list for computer troubleshooting!

  1. Your computer isn’t turning on? “Oh, no!” You think, “I’d better get a new one!” STOP right there. Before you get too frustrated, be sure you have checked that the power cord is actually plugged into your wall socket properly. You may think it sounds silly, but believe me, it’s more common than you think — even for the computer savvy. If your computer is connected through a power board, you should try plugging it directly into the wall (note for the safety conscious: by plugging the power cable directly into the wall, you lessen the chance of power failure and damage to your machine). Another reason that your PC may not start is if you have made any repairs or modification to your machine. You may have unwittingly pulled out a connect plug; check all connections.
  2. If your computer is starting but is spitting error messages at you, then you might need to take out any memory modules such as RAM and then reset them by plugging them back into different RAM slots.If you get an error such as ‘Unexpected Interrupt in Protected Mode,’ then there is a problem with the settings you have entered in BIOS. To fix it go into BIOS and set it to default settings. If the problem still won’t go away, then you must remove the CMOS chip on your motherboard then put it back in to clean BIOS completely.

    Another common error message is ‘NTLDR missing.’ NTLDR is the first file that executes in the boot process; it can get moved or deleted or even corrupted, so restore the NTLDR file from the Windows install disk.

  3. “My LAN isn’t working… I’d better hire someone to do it!” WRONG. If your networked computers aren’t communicating…
    1. You may find that resetting your router will solve everything. If not, look at each node’s IP/TCP configuration to check if each node is configured properly so no IPs clash.
    2. Check your cat5e or cat5 or even cat6 cable to see if they might be the problem to your faulty connection. Try connecting the suspected faulty cable to another computer and check to see if that computer connects to the network.
  4. How to test if your NIC is really working. The best way to do this is just by pinging yourself. Go to run, then cmd, then type ‘ping 127.0.0.1’ — it should then send you four lots of packets and test for the connectivity. If it’s not working, then most likely, as previously stated, your TCP/IP configurations are incorrect. To change these, go to start, then control center, then network connections, then TCP/IP and check the ‘obtain automatically’ button.If you can ping computer C from computer B but not the other way around, this is most likely because of a firewall set incorrectly within your networks. Firewalls are common pests when it comes to connectivity errors within a network.
  5. Screen is black?
    1. First, check the connectivity of DVI or whatever you use to ensure that it is actually plugged in.
    2. Check your graphics card on the motherboard as it is responsible for the graphics on the system. Make sure the fan is still spinning and that it’s properly connected to you motherboard outlet. Then check the heat of the graphics card — if it is unusually hot, then you have an internal problem.
    3. It is also possible that it isn’t even the screen — it could be your boot process. Follow the previous steps to restore your PC.
    4. Check the RAM — it has been known to cause video problems.