Firast thing if you are upgrading, CHECK THE RAM!! 7 needs at least a megabyte of working RAM. Mind you cheaper to upgrade RAM than a new computer. I use a company on the web called ORCA, great service and cheaper than any local supplier. Might not directly help with printer though. I have a HP Desckjet F2200 series. Took my a while to find out you need a patch for 7.
AVG do a nice computer check up and service programme. There is free version but I've got the paid version, really do see the diffrence.