How much memory do you have? If you only have 2GB, an upgrade to 4GB could make a big difference. Crucial.com can show you what memory you have and need and give you a quote, although you can actually get it cheaper elsewhere. If you want a whole new system and all you do is basic stuff then a low-end box at Dell or HP or Costco in the $300-$400 price range will be fine, just make sure it has at least 4GB RAM.
Cheap laptops are pretty good these days too, you really can’t buy a new one at any price that would be inadequate for basic stuff.
