I've got a 5 yr old compaq that lately has been running really sluggish. I run regular virus/spyware checks using AVG and of course it's also doing real-time scanning. There aren't any processes running that I'm not expecting and none of them are hogging all that much memory. I noticed that my total physical memory is around 391 MB and it should be 512. I don't really know the expected difference between what the manufacturer states and what is given but I would guess it's less than 100 MB. I'm running Windows XP SP3. Are there any known problems that might be causing a sluggish computer or are my instincts correct in that I have a problem with my physical memory? I would also appreciate any other suggestions you might have for such a sluggish computer.