Since this is an office computer it may be locked to prevent this from happening. This is the only reason that I am aware of that can cause this to happen. Either there is a BIOS lock or an admin lock preventing you from doing this.
1) for the admin lock you must contact the admin for the unlocking it.

2) I have heard tell of an embedded BIOS from some manufacturers that had a specific rule that would not allow the format or installation from another source except for the disc that was used to install the operating system originally. I have yet to run across one myself but have heard from others concerning this.
If I remember right it took a computer engineer from a certified repair shop to repair this as it takes a special BIOS program to open the lock! This program is only sold to certified manufacturer authorized repair shops and can not be obtained any where else. You can call the manufacturer and ask them about it and I believe that for a fee they will or can do this over the phone and through remote access.

Good Luck!