SCANNER SOFTWARE + OCR

I have a scanner (Acer 320u). It worked fine on Win 98, but I cannot get it to work on Win XP. Benq bought out this product from Acer and the drivers they offer do not work. I found one that does work ‘VueScan’ except they only gave me a trial copy for free. They want $40 for the full version. I want to avoid spending any more money.
HELP!
RHS