Recovery isn´t working...?

Hey,
I´ve been trying to fix my girlfriends computer for some time now and I´m having a bit of problems. The thing is it´s an 11 month old laptop and it´s running slower than the very first computer that I ever owned. The problem isn´t in the memory because it has 2GB of memory and I´ve checked and verified that both are working properly.
As a last resort I´ve saved all her important information on a second disk and tried to do a recovery. I have the recovery CD that was made right after purchase. Now comes the issue, it´s her computer, no one else is using it and there´s no administrator account present. When I tried to do the recovery it gave me the warning that I´d loose everything from my disk (which I´m aware of) and that it would basically go back to zero. PERFECT, that´s exactly what I´m asking you to do.
The catch is, that it gives me a warning that the C drive is protected and I cannot erase everything that´s present. So does anyone know how I can get around that protection and force the computer to take the recovery so it can go back to zero? Don´t even ask me why it´s protected because it seems like it has been like that since it was bought.

You can install your Vista installation over the current one after your install has been completed and you are booted up you will see a file in your C: drive called windows.old you can either restore from there or your back ups.

That´s the biggest problem... I don´t have the original Vista DVD because it wasn´t supplied with the laptop. Windows Vista was pre-installed so all I have is the Recovery disk. I already went back to the computerstore where this laptop was purchased and they said the recovery disk should fix it. I raised a big hell that it was absolutely retarded not to give the Vista DVD with a 2000 euro laptop. But all they gave me was a rude answer and the question to leave.

The current C: drive (Vista partition) is protected because your product key is bidden to that installation upon activation. You can borrow a Vista dvd if you know anyone which owns one. Have you completed a system restore to the furthest possible restore point and cleaned up the registry before doing a fresh install? You can get C: cleaner from the link provided it's freeware and allows multiple functions like registry cleaing, scanning etc

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