PC will not start

[LeedsRhinos]

Can someone please help? My PC has been doing strange things lately like locking up and rebooting by it's self. Now this morning it wont start at all it is coming up with the message-- Invalid system disc, Replace the disc and then press any key.
Any suggestions will be gratefully received.
Thank you in advance.

[Kerplunk]

It could be any one of a few things,  faulty HDD, faulty ide cable, faulty BIOS config, corrupt Windows installation, faulty motherboard.  What o/s are you running?  If windows 2000 or XP try booting to the installation cd and choose install windows.  When / if it finds the current installation choose repair.  If this doen't work then it is most likely a dead HDD.

[vehelpfulguy]

I had a problem like this a few months ago. Someone suggested it may be dust and dirt inside the case.

When I took the cover off I was amazed at how much dust and dirt there was around the fans and heat sinks.

If the fans are not working properly the PC components get too hot and they fail.

If you are happy to do this, remove the covers from your PC and blow out the dust and dirt with a hair drier. Use a small clean paint brush to brush the dirt off the fans and heat sink.

You could also use a vacuum cleaner to suck out the dirt, but beware of touching the PC parts. Maybe sellotape a straw to the end of the vacuum to get in the small gaps.

After I did this everything began working Ok again.  

[Hammer]

You haven't left a floppy disc in the drive have you?

[joko]

the error message is a floppy left in the drive - remove and try again. you can buy compressed air cans to clean components fairly cheap - try viking direct. be careful with a hairdryers heat settings - cool is best

[Kerplunk]

The error message could be a floppy disk in the drive but not definately.