I wouldn't expect miracles from an Atom-based machine but a reformat and fresh install will at least bring it back to as-new speed, assuming there are no hardware faults. Windows 7 starter is limited to 2GB of RAM so you won't be able to upgrade that unfortunately. You could consider changing the HDD for a small SSD which would improve bootup times, program load times, and so forth, but I'm not sure if it would be cost effective for a 5 year old netbook.