On a recap, if you have a System Repair Disk you can boot up with that which will get you the Recovery Environment without the need of a password to select System Restore, but you would need to change the boot order in the BIOS (Setup) for the machine to check the DVD drive first.
If you haven't created a System Repair Disk, these can be created on any Win 7 machine that has the same architecture as yours - 32 or 64bit, but a 32 bit cannot be used on a 64bit machine or vice versa.
Do you know anyone who has such a machine ?