Windows Vista 32bit Dell Studio 1555 Failed To Start

Well, yesterday I was mindlessly updating my itunes, just the normal moving/remaining song etc., when my laptop shut off unexpectedly. This has happened before over the last two years due to over heating and it was very very hot at the time. Now when it's witched back on I receive this message:

Windows failed to start. A recent hardware or software change might be the cause. To fix the problem:
1. Insert your windows installation disc and restart your computer.
2. Choose your language settings, and then click 'next'.
3. Click 'repair your computer'.

File: \Windows\System32\drivers\volsnap.sys
Status: 0xc0000098
Info: Windows failed to load because critical system driver is missing, or corrupt.

So...There's been no changes to my system in months-it's been working amazingly, and I never received any kind of disk with the laptop when I bought it-not sure where to get those then. I'm not overly up on the idea of paying for something I was supposed to be given when I paid for the laptop, so alternatives would be appreciated!
I've tried quite a few methods already, f8 which doesn't give me a repair option, other f keys which seem to just lead back to the same screen, even had a go at creating a vista recovery disk which hasn't seemed to work, unless I'm doing it wrong!

So, yeah, any help would be appreciated, I can't seem to find answers anywhere!

Welcome
I may have a solution. You will lose your stuff, however. If you have stuff to save post and I will tell you how. If you just want the computer fixed, give this a try:
Ctrl + F11 or F8 - Access Dell computers Dell System Restore (DSR) partition on many different models.
If it works, you are restored to the way the computer was the day that you purchased it. You have to reinstall your programs, updates, SPs etc.

well i would like to keep my stuff if it were possible. however neither of these options seem to work. i can access the advanced boot menu but it simply leads back to the original message. i do have a D:recovery drive if this would be any help

The recovery drive is what we are trying to reach with the post that I made to you.
Before trying anything, why not save your stuff
Use Ubuntu Live CD to Backup Files from Your Dead Windows Computer - How-To Geek

Well, I successfully managed to create the ubuntu CD, and it does work, I tried it on other laptops. However, my laptop is refusing to boot from a CD. Am I doing something wrong? Or is there now another problem that needs fixing with the dvd drive?

Nothing wrong. Try resetting the boot priority.
http://www.vistax64.com/tutorials/205005-boot-priority-change.html

Already done.made no difference.

Set for IDE if necessary
How to Change SATA to IDE in BIOS | eHow.com