Getting error Message when trying to install software

I hope I am posting this to the correct area.

A friend of mine has an Acer laptop with Vista Basic 32 bit.
We are both machine embroiderers that use various embroidery software. In
trying to install Embird, which like I said is embroidery software, she
continues to get the following error message:
*********
Warning
Can't write to Windows Registry!
Key: HKEY_Classes_Root\.psd
If you are running Windows, NT/2000/XP/Vista,
please log on as administrator.
**********
She is the admininstrator and she is also the only one using that computer.
We have tried having Admininstrative Controls on and we have also tried right
clicking on the install file and clicking 'run as administrator', but still
get the error.

Please keep in mind, that I am an XP user, so what I know about Vista is
just things I've read. She is a beginner. So we are like the blind leading
the blind. LOL

Any help you can give me in trying to resolve this would be appreciated.
Please don't talk techy.

Thanks so much,
Judy F.
SW Florida - USA