What you want to do is not 'crash' your laptop. (A crash is the last thing one wants to happen to a computer!)
Some people reinstall Windows to fix slow running computers but it is a dangerous (and sloppy) practice and so not recommended. (I suspect that it what you are trying to do.)
Here is how to fix a slow PC:
Install more memory (RAM).
Cut down the number of programs at that run at startup.
Defragment your hard disk.
Use a registry Cleaner.
If you really do want to reinstall Windows you need to look for a 'recovery partition' on your Hard Drive (In the manual) or buy set of recovery disks from the PC's manufacturer.
T, December 2008