Well, the good news is that your laptop is fine.
The bad news is that your installation of Windows (I assume XP) is stuffed.
Your data should be fine - just the system files are screwed, so it won't boot.
There could be an issue with the disk, but this particular corruption usually occurs when all power is removed from the PC when booting or closing down (which are just about the only times this file is read from or written to). Or a severe jolt instead can have the same effect.
There is a possibility that you can use either the WinXP CD or another bootable CD to go into C: \WINDOWS\SYSTEM32\CONFIG and rename "SYSTEM" to "system.bak", then copy s"ystem.sav" (this is default, but the extension on your PC might be different) to "system". You will be doing this at the command line, btw.
The system might now boot - assuming that the backup file was present and that no other files are corrupt. But depending on how old the system.sav file is, the system may not be usable - worst case is that it returns it to the state when WinXP is first installed (and you will need the XP CD to finish the installation. You can do this, your data will be safe, but it is a pain, as you will end up with a parallel install of Windows, and your old users will no longer be accessible (see below about transferring user settings).
However, a more certain approach would be to back up your data - either by removing the disk and using a 2.5" USB caddy to connect it to another PC, or attach it to the inside of a desktop PC with a 2.5-3.5" IDE convertor. You could even boot up with a Linux distro that installs off CD, then connect to a network and move the files off to a network share, but this is more esoteric!
Once you have all you data off, then you can do a clean and complete re-install (reformat C: while you are at it, but don't delete or reformat any other partiitions).
If you are lucky (or foresighted enough) to already have a D: drive on the system, then your data will probably already be on that partition, so some of your work is already done. But don't forget that a LOT of stuff will be in C: \Documents and Settings\yourname - email, favourites, My documents etc.
So well worth extracting that.
If you are concerned about the disk - or want an excuse to get a bigger one - buy a new disk and an external USB caddy. Put the new disk in the PC and the old one in the caddy - backup instantly sorted!
SD