The HP website says there is a driver in VISTA but not fully featured.
But it should get the printer printing.
Have you succeeded that far?
You might try going to the Printers section of COntrol Panel and
deleting any icon(s) for the 7150 printer and going into Device Manager
and deleting any references to it there (look at the bottom of the list
in the USB section -- I have an entry there for my PS 8250).
And then rebooting and let VISTA try to install it again.
HP Does have a document on using alternative printer drivers but
although it comes up when you search there for your printer and then
for VISTA it does not mention the 7150. But if you know enough about
the 7150 you might try any drivers that are for similar HP printers.