Thanks for the replies!
Task manager reports about 1.24gb being used out of 4.
I'll start running some virus scans.
Computer is about 4 years old, here are its specs:
(It's a dell XPS 410. Most of the hardware is whatever dell installed, but for two 1gb sticks of ram. If you need me to check on exact brand/model of anything or any other specs, let me know.)
Running Windows 7 Ultimate
Mobo: Dell Phoenix ROM BIOS Plus version 1.10 2.3.1
Processor: Intel Core 2 6600
Memory: 4x1gb DDR2 667MHz
Hard Drives: 2x250gb in raid 1 array
Graphics: ATI Radeon HD 4850
Power Supply: 375w factory installed
Not sure what specs would be helpful, so I think I covered the main stuff. Thanks again for your help