When I called, they told me just to bring everything in and we'd talk about the best way to move forward. I was afraid they'd tell me I needed to buy a new computer. As it turned out, I didn't need to buy a new computer, but I also couldn't use the gift certificate (boo) - what I needed was to have them install the new software and give my machine a good scrubbing.
It was ready in a couple of days, and I only needed to download the software for my printer, and the anti-virus software (both updates, which I should have had anyway). It already had iTunes, and all my internet bookmarks, files and photos.
They recommended coming back in a year to use the gift certificate for a tune-up (just like I do for my car! brilliant), and I may have them set up my wireless printer in the meantime. The "store" in Bethlehem (near Liberty High School and Jumbar's) is open M-F, 9-5, but technicians are available for appointments almost anytime.