Changing Printing Permissions in XP

I recently acuired Windows Vista for my lap top. it was previously running
XP, and I had a nice netywork set up between my lap top and my mom's XP-based
desktop. But now that i've acuired Windows Vista, I'm having a hard time
setting up the network. i managed to gain acces to the shared folders on her
computer, btu i still can't seem to be able to get to the printer. It's an
HP Photosmart 8200, and everytime i try to add it, it says "cannot access
device, access is denied." I can even browse into her priting folder and see
the printer, and what's listed as a printer (like a document writer for
MSOffice), but when i try to click on it (the only thing I've clicked was the
photosmart. that was the only thing I wanted.), it would say the same thing;
"Cannot access device: Access is denied."

i think i read somewhere on here that this was a simple permissions problem,
but I can't figure out how to change the permissions. I tried running the
set-up network wizrd [again], enabling file and printer sharing (which was
already previously enabled), but that didn't help. I found that if i told my
mom's computer to not share the files, and then share them again, i was able
to access them. But that didn't work with the Printer. I am at my wit's in.
I managed to figure out that the computers needed to be on the same
Workgroup as they was before, but I cannot seem to get past this barrier
between my laptop (wireless), and my mother's printer. Can someone please
help? If this is merely a permission's problem, how do i change it in XP so
i can add and use my mother's printer?