The PC's in question are a Dell Dimension 4600 (Pentium 4 2.8GHz, 80 GB HDD, 1GB RAM) and a Dell Inspiron 6000 laptop (Pentium M 2GHz, 80GB HDD, 1GB RAM). Both are now running WinXP SP3 and both PCs are still in excellent condition. All RAM slots on both machines are populated and as old DDR2 RAM is quite expensive, I'd rather not invest the money to increase RAM. The only reason I'm even thinking about replacing XP with Win7 on these PCs is XP's imminent EOL and therefore becoming a major security risk - my 2 kids use these PCs mostly for MS Office apps, email and surfing the net (frequently!). My only concern here is how to make W7 SP1 run on these PCs as well as XP SP3 now does without compromising their ability to receive/install W7 updates! Any advice/tips would be appreciated.