|Probably not. I don't think the restore disks have an option to just restore the system files but it wouldn't hurt for you to check. If not, an 'over the top' reinstall with a regular ME disk would do that and preserve your files.|
But 'Operating system not found' can mean a bad hard drive so you need to check that out first. Open the case and verify the hard drive cable is in good condition and tightly connected. If you have an option in cmos/bios setup for HARD DISK PRE DELAY, set that for 6 seconds or so. That gives the hard drive more time to spin up and be recognized. Then boot it up. Maybe that'll fix it.
If that doesn't correct the problem, I'd boot up with a 98 or ME bootdisk and try to access the drive with the dos commands on the bootdisk. If a DIR command on the c: drive shows files and directories then a restore of only the system files (if possible) or an over-the-top reinstall should work.
Another option is if the files are there they can be copied off, either with floppies, adding a second hard drive and copying to that or installing ME on a second drive and using the old drive as a slave and copying the files to the new drive.
I guess it kind of depends on your computer expertise and what hardware you have available. But first you need to verify the drive is good, otherwise getting you data is all but impossible.