There are certain simple things to try with a malfunctioning computer that can save a great deal of time if they work:
Check for power.
Reboot (after removing the floppy).
If the computer is locked up, you’ll have to turn off the power, wait 30 seconds, and turn it back on. On ATX systems, which have a soft power switch, holding down the power button for at least four seconds will almost always shut the computer off.
Boot from a boot floppy.
Reinstall or roll back a device driver.
Reseat expansion cards.
Disconnect and reconnect connections.
Clean adapter card contacts with a pencil eraser.
Replace the power supply.
Run ScanDisk and Defrag.
Check Windows Device Manager.
Check for a software patch or update.