This is related to a previous post of mine...

I have a Dimension E521 with Windows XP Media Centre.  A few months ago I had a blue screen error for which I had to contact Dell Support.  They got me to recover the OS without having to lose my files, and all was well until I decided I wanted to do a factory reset because the computer needs a bit of a spring clean:

The shift+F11 command to do the system restore will not work - possibly because of the reinstallation of XP being somehow flawed.  It has been reccomended that I reinstall XP again but when I go into the setup, press R to recover the OS and selct the (only) OS I want to repair I am prompted for an admin password.

I do not remember ever having set a password other than the one for my user account, and that doesn't work.  Nor does any other password I may have chosen.  I have tried leaving it blank as well as 'password'.  I can only assume Dell must have decided to put on a default password and failed to mention it.

Is it possible to reset or remove this password or otherwise find out what it is?

Help would be much appreciated, thank you.