I've got a problem the Sony tech support can't help with so far. (I've got a Sony Viao puter)

Computer came with HD pre-partitioned as a C: and D: drive.  C: drive, 15 gig was 75-80% full out of the box with pre-loaded software.  the D: virtual drive was 92gig and empty.  Intended purpose of huge D: is for recording live television or video and editing.  I have a external hd (120g) for primary back up.  I'm using windows xp home SP2 and Norton internet security 2006.  (I suspect norton for some reason)

Some time back I created a new folder on D: drive "program files" to load new stuff to because C: was about to burst it's seams.  Over time D:/program files has grown to include about sixteen programs including things like Wings3d, Grass3d, Daz Studio, Ad-aware,knotplot, PS7, Norton IS, etc...  Several months ago I acquired broadband and upgraded to Service pack2,  about 30 days later I upgraded to Norton IS 2006 also.

Everything runs fine.  I can run programs within the folder fm desk top, start menu, and clicking .exe icons within the folder.  What I discovered about a  month ago, too long to do a system restore, is I can no longer add/move/change anything to or within that folder.  "access denied"  Now it is a big problem because Daz studio resides there and I can't install new critters into studio:  or add plug-ins, "access denied".  Safe mode doesn't help.  I can't un-install programs to start fresh. "access denied".  I am only user with admin abilities.  Logging in as Administrator in safe mode doesn't help. 

I'm concerned about reloading stuff somewhere else without uninstalling first in the hung up folder.

I suspect Norton for some reason since it resides there also. 

Anyone heard of like problem?  Any resolution ideas short on starting completely over?  I've googled and surfed tech forums to no avail.

Tks Willie