locked out of admin privileges.

i was recently configuring my network in my windows vista premium on a dell
laptop. so the next day i was locked out of all administration privileges. i
did not create a new account or something so i'm still the local admin.
now the problem is i cant do anything other than surf the net.
i cant download anything, run the D: drive (it runs or 'spins' but wont
open/read cd/dvds, it brings out a message stating access denied or som like
that.), or even make changes in the computer like turning off the UAC. i just
get a message stating i dont have admin privileges.
i have found several ways i can enable the built in admin which would help
me with ma problem but at the end of it all i still end up at square 1 coz
either i have to download something or make some changes in the user
management which brings up that annoying "dont have privileges pop up". i
cant even access symantec to run a virus scan!!!
on safe boot, the comp simply freezes or something coz when i click
something, applications dont open/run.
my last solution is to save all ma docs(50gig lol!!) then run an iso i have
that would clear all data and then reinstall vista. but its tiring and time
consuming.
could someone pliz help me out.
thnx