Vista Recovery disk problem

I am using a Dell Inspiron 1420 and Vista Business, it would not boot up and ran all the Microsoft suggested fixes to no avail. So I reinstalled Vista and drivers etc. but now my D drive is full and I cannot empty it, everything seems to be writing to that drive and not C, sure it is my fault but don't know what to do now?

It looks as the the path for everything important goes to the D drive, should it not go to C? Obviously I am continually getting disk full messages and cannot delete anything from that drive even though I am the administrator.

Any help would be appreciated, Thank you!

Processor is Intel Core Duo CPU T7250 @ 2.00GHz 2.00 GHz

 

Had a similar problem with an XP install once, installed with an external hard disk drive attached and running. When the install was complete the external drive was C, and the primary was D. Reformat and reinstall seemed to be the easiest solution, Microsoft frowns on too many calls for activation in a given time period so don't activate until you are happy with the results.