Personally I'd have a minimum of 2GB RAM and decent sized HDD. Here are the Minimum System Requirements for Windows 7 via MS
Also really depends on what you are going to be doing with your computer? Basic web and Office or Gaming as well. Decent PSU as well is always required for any PC.
Also really depends on what you are going to be doing with your computer? Basic web and Office or Gaming as well. Decent PSU as well is always required for any PC.