I has windows XP but while I was reinstalling it the CD broke. I could not afford a new windows XP disk, so I bought windows 98. When trying to install it It keeps giving me "invalid system disk", and then sometimes a message pops up that says "media test failure" I really dont have alot of money to have this fixed by a pro so if you guys could give me any kind of help that would be great.

Your window XP CD "broke" then you have problem reading Windows 98 CD. Seems to me you have a problem with your CD ROM. When that happens there is little choice but to get another one. There is nothing inside them that can be repaired. Stuart

It could be that the drive has the NTFS file system. Dos/Win98 can't access it. Download DElPart and run it to remove all partitioning on the drive. Run fdisk to repartition and then format the drive. Try the install again. DelPart is available at: http://www.russelltexas.com/delpart.htm

Cd broke? Interesting turn of phrase. They are about impossiblie to physically break so can we take it that you mean it became unreadable? Might be worth browsing it on some other machine to make sure it's not your CD player that is the problem. Derek.W

"media test failure" will not be resolved by delpart and hard-drive reformats etc. - if the message refers to the CD. T'would be wise to check if the XP/'98 CDs will "play" - i.e. can be read - in another working system. If it can, then the CDROM in your PC probably has a problem? You could try running a CD cleaning disk thru' it; these effetively clean the lens assembly - which can get mucky - error message similar to the one you're geting can result. Compu$a sell one for a few $$; usueful item to have around for any CD/DVD system (PC/hi-fi/video/portable). It may also be an internal electronics failure (there are some compents inside that can fail - as can all solid-state kit...). Intermittent/failed internal sensor switching likewise? Internal parts can be replaced (at a cost...) Less likely is that the head system is not tracking (properly - if at all) across the disk - a problem that occurs on conventional CD/DVD kit. The assembly is sparingly lubricated and this can dry out - thus the head does not track properly (if at all), and one of the error messages offered up is the message you're getting. These units can be cleaned/relubricated (certainly the doemstic hi-fi/video systems can be) but on this occasion it's hardly worth effort. A replacement should cost very few $$$/£££'s these days; especially at a comupter-fair/clearance house. Recently Sony DVDROM were going for around for £15/$20 at a "computer-fair". Check your disk(s) are OK first in another working drive and go on from there. If possible borrow/install a known working unit to verify if a replacement resolves the issue; and presuming so go on from there (replace the duff unit)?