content: Upgrading my old Dell D620? This thing doesn't use much power. Being off grid, I like that. It came with Vista which I then replaced with XP.  Well....I liked XP. Now XP has lost some functionality due to lack of support.  Having just upgraded the memory to 4GB and the DVD ROM with DVD-RW.....thinking I should also consider putting in Windows 7. Not being a techie at all....wondering if I should just put in Windows 7. Or perhaps replace the 100 GB hard drive with ~320 GB and Windows 7 pre-installed. The costs appear to be similar when looking at used hard drives. CPU is Intel Core 2   T7200@2.00GHz   Thanks in advance for any help that may be received.