I have an older Dell desktop that is running Windows XP. All of a sudden, I keep getting messages that my "virtual" memory is being used up, and to shut down and restart. It seems to freeze everytime I try to do something on it. I run AVG free on it. I have also run Malaware Bytes Malware on it, along with Spybot and Ad-Aware. It even seems to freeze when I try to do a defrag. Is this computer on it's way out?