There is a reason for putting all the installation files in a separate place on all system hard drives. It's spelled M.O.N.E.Y in the real world, and "Instant Upgrades" in the Microsoft world.

By having all the files necessary to run any version of Windows on every hard drive, all you have to do is call Microsoft and give them access to your bank account, and they can tell you what "unlock code" will convert your "basic weenie" Windows version to "super-gold-plated-plays-every-game-in-the-book" Windows.

Since they figured out how to give you upgrades (for which you pay them money) without ever sending you a disk, they were clever enough to also figure out that they didn't have to ever give you a disk for any system.

They did make it possible, if you want a disk, to export a "disk image" of your original installation files and make your own. And it saves the "sellers" (actually mostly the OEM builders) about $1.38 per computer sold. (It all adds up over a few million computers, I suppose.)

The "Instant Upgrade" began to creep in with WinXP, and a default installation put all the files necessary for a new installation on the hard drive (mostly in .CAB files) for all versions at least since Win95; but earliest versions omitted the "install" program, so the .CAB files were available for some System Repair functions, and for some upgrades after WinXP, but you still needed the disk to do a new install. Disk cleanup also offers you the option to remove the system backup files to make more space available, and lots of people apparently do wipe them off the hard drive.

It's implied that for Win7, and possibly for Vista, the "recovery files" are sequestered where you can't delete them accidentally even with an "intentional accident," but details are vague.

It appears that Vista and Win7 have it all on the hard drive but, as in the present case, if you can't boot you can't reinstall, so you do need to make a "boot disk" for disaster recovery.

Those who use passwords (as everybody should) also need to look at whether they want to make a "Password Recovery Disk" (or flash drive). Corruption of the "password locker" is NOT a rare event with recent Win versions. A Password Recovery Disk can replace the corrupted file. Without one, you may have to reformat and reinstall from scratch in the event of what would otherwise be a few bad bits on a drive.

Bad clusters on hard drives are actually a fairly common thing, and most files can be repaired automatically and invisibly by the hard drive controller - by moving the file to a good cluster. Since the password locker is encrypted (with very strong encryption) the files cannot be moved and any localized defect corrupts them completely and can't be repaired.

The instructions for making a Password Recovery Disk are dependent on system details and also on what system passwords you've used for which access privileges, so consulting Help files on your machine are your best approach to making one. Note that you may have to log on as Administrator to make a Password Recovery Disk that repairs all the passwords for all users, although I believe each user can make one to repair only his/her own password.

John