For XP – A computer with a Pentium processor, at least 512MB of RAM (operating memory), preferably 1 to 2 GB of memory and an 80GB hard drive or larger.

For Vista – A computer with any dual-core processor, 2 to 3 GB of RAM and a 160 GB or larger hard drive.

These hardware configurations will minimize Page Filing (swapping programs in and out of memory and onto the hard drive) and assure that your computer has enough horsepower to run the operating system. Upgrading memory (RAM) is the cheapest and easiest thing you can do to improve the performance of your computer.