I've had this problem and It's frustrating but usually not too bad as long as you have your installation and or driver disks. If it's from before Windows 7 you should have one somewhere around but If it is Windows 7 you kinda had to make it yourself and I believe your only allowed to make one.
Now if you don't, don't freak, you could get one from the company associated with your laptop,or windows directly (they should be free but you may have to pay shipping and handling), worst case get one from some tech store. They will charge you and arm, then bring it back saying it wasn't what you thought it was, your not reinstalling your OS (that would wipe your old stuff) your just doing a recovery.
Try reinstalling Drivers first.
First try using the Driver disk in safe mode or another regular start up way and fixing your drivers from in safe mode or regular start up or if that doesn't work try the following but with the Driver installation disk.
Step 1 of Startup Repair or a Systems Recovery.
Then on next boot put in the disk and press F12 (should be somewhere above the keyboard minus sign) on boot up as soon as you can.
Now boot from disk instead of the "C:" drive and follow the instruction.
Once pass the prompt asking you to install Windows
Do not reinstall the OS
You should see this after...
Click Startup Repair first (don't worry if it take a hour (probably won't but you never know))
It should restart and work
If not do Steps 1 and 2 again but in step three click Systems Recovery.
Now if that does not work contact me again (or if you don't mind and need it now you can reinstall and wipe everything A CHOICE I NEVER CONDONE)