I have switched on/rebooted my PC but it's come up with a blue screen with white text and numbers all over it, what can I do?

Your screen looks similar to the following: It is sometimes called the Blue Screen of Death or BSOD.

This blue screen "stop" error indicates that something has gone wrong with your PC. Make a note of the first three lines of text, starting with the *** STOP: line. E.g. for the screen above write down:

*** STOP: 0x0000000A (0x00000000, 0x0000001a, 0x00000000, 0x00000000)
IRQL_NOT_LESS_OR_EQUAL
p4-0300 irql:lf SYSVER:0xf000030e

Then reboot your machine, either by pressing the reset button, or by switching off, waiting ten seconds, and then switching back on again.

The machine may boot correctly this time. However if the blue screen error re-appears and the first three lines of text are the same as the details you noted down before, you'll need to contact the IT Support Centre.

If the blue screen re-appears but the details you noted down are different, make a note of the new details, then reboot the machine again. Continue this a few times until either the errors are the same, or the PC boots correctly. If the blue screen error does not go away, contact the IT Support Centre.