i have a presario x1030us.. problem is the hard drive sometimes it
will work fine and sometimes it will say non system disk, disk error.
i will usually wait a couplw of days and it will work fine again, it
will boot up properly. i have checked the hard drive connection,
installed a fresh copy of xp pro and its not definitely a virus
problem. is it the hard drive that has a problem? and how do you take
a worn out or rounded damaged screw head. thank you

As for the hard drive, 
GET ANOTHER ONE FAST, you may end up loosing more then just a hard
drive. You may end up loosing your information as well.

Key suggestions, get a new hard drive, disconnect the old one and put
the new one in. After you load your OS (operating system, like 98 or
XP) take the old hard drive and plug it into one of your CD drive
ports, then using XP's transfer program transfer your information
over. There is also a way for you to test the integrity of the hard
disk and the disk drive itself, but unless you are extremely computer
saavy, you may not understand what your doing.

NOT calling you dumb, just going off your question.

Sorry, 
as for the screw, take a drill and a drill bit that is roughly 1/3 the
size of the head of the screw and drill the screw through, ONLY
alittle bit, then reverse the way the drill moves and it should
unscrew the screw.

Only bad thing about this is, you have to get a new screw.

You could also take a Dremel and put a notch in the top of the screw,
so a flat blade screw driver will fit that notch.

I've done that a lot of times to backout a screw when it gets slopped out.

Good luck!

Gosh, that is the message one gets if there is a floppy in the floppy
drive during boot, if the BIOS is set to look at floppy first before
Hard Disk.  I realize most new computers today don't have floppy
drive, but if yours does, go into the BIOS and change boot order so
floppy is not above Hard Disk.

In fact, you could put HD on top, and if you need to boot on something
else, go into BIOS and change it back temporarily.

The other posters may know a lot more than I do, and thus they may
have a reason to blame the HD rather than another device, but I did
think to mention this.