Have recently acquired a printer which links to PC by usb cable rather than power cable. Since then everything has slowed down, am getting low virtual memory messages, the printer is not working very well, and the pc often freezes. I regularly scan my disk, defrag and try to ensure that nothing unnecessary is running in background.
There may be an issue with either the printer software or the printer drivers. I would suggest uninstalling the printer and downloading new drivers from the website of the printer manufacturer.