Install Windows on Encrypted HDD

All,

Another day another question. I recently bought a a bargain HDD off ebay for my laptop and found it is protected. When the machine is turned on it asks for an encryption key - (PointSec software). I have no clue what the password is and would like to know how I can wipe this disk clean and install windows fresh.

Here are the limitations - I do not currently have any other PC's running windows/Linux. Only a Macbook. The laptop i put the HDD into has no disk drive - so can only boot from USB.

I figured this would work - but need a little guidance.

1. a Create a windows image on the USB (but i dont know how I can do this without actually having an original Windows on a CD)
1. b Create a Ubuntu image on the USB (if i create this using Mac OS, will the image load on a non Mac machine?)
2. Boot machine from USB
3. Install Windows / or / Ubuntu
4. Wipe HDD clean.

However i dont think this is well thought out. Will I be able to boot from a USB before the encryption software is loaded?

Can anyone think of a another solution to this problem?

Appreciate it.

Thanks