*Spent Entire Sunday* on this, (User Account Control)-please help :(

Hi everyone, I will try to be as brief as possible with this but I want
to make sure I explain all the details as I am stuck and not knowing
what to do at about 8 PM when tomorrow is a workday :(. Anyways...

Windows Platform: 32xVista, Comp: HP 6700 ; To start off, I was an
idiot and was installing some program a friend had given to me and it
required "New SID" from Microsoft and I did brief (obviously too brief)
research on Microsoft's site and I went to install it. It sat there for
literally an hour and I thought the process had froze but did not know
what to do so I ended up ending the task from the task manager... and
when I restarted....boom! Everything changed and disappeared...

So on my desktop everything with the appearance changed and I am
shocked to discover that I no longer have Administrator access, my
useraccount *User* has only guest privileges (and I went online and
spent hours today doing a search with people with similar problems) and
went through Safemode....went through other procedures to try to access
my account but I'm unable to! The weirdest thing is that I am able to
log on to the "Administrator" account when I am in safe mode but, and a
big but.....my Admin account in safe mode is also under Guest status and
I can't do anything to stop it!

Under "Users" folder I can view all the user accounts I see the
following: ADMINI~1, Administrator (recently created & showing),
Default, Public, Roaming, *User Account*, *UserAccount.UserAccount-PC* &
NTUser.dat; now...I had a fingerprint reader (the Microsoft one)
installed from before and the weird thing is whenever it asks me for
administrator permission access, it asks me to input my fingerprint but
when I do, now it doesn't work! In Administrator mode that I was
in....it wouldn't even have that and it would be blank and wouldn't let
me click on "ok" to give me admin. access.

I also don't have access to the *UserAccount* folder that used to be
the one I always used and had access to and while I am logging on that
same name....it appears that I am using *UserAccount.UserAccount-PC* .

Other than that, I have my current SID# but am I somehow able to change
my SID# to the previous one and is there a way I can find out what that
# was???

I have VERY Super Important files so I can't just reformat it without
losing my important data files....I don't mind losing the program files
and to reinstall each and every program (as long as I am able to get a
list of the names of the programs) if possible.....but save my data and
then reformat....but someone please help me as I don't know what else to
do. I am pretty computer savvy but I am just stuck out of options....any
help? Thanks again in advance for anyone willing to try to help me, I
want to pull my hair out! Again thanks so much, and I appreciate the