If you have to post the question, then you don't need raid of any type.
I know; smartass remark, but no offense intended.
There is generally no real world(vs. synthetic transfer rate benchmarks) performance advantage to raid of any kind.
Go to www.storagereview.com at this link: http://faq.storagereview.com/tiki-index.php?page=SingleDriveVsRaid0
There are some specific applications that will benefit, but
gaming is not one of them. Even if you have an application which reads one input file sequentially, and writes
it out, you will perform about as well by putting the input on one drive, and the output on the other.
The value of raid-1 and it's variants like raid-5 for protecting data is that you can recover from a hard drive failure quickly.
It is for servers that can't afford any down time.
Recovery from a hard drive failure is just moments.
Fortunately hard drives do not fail often.
Mean time to failure is claimed to be on the order of 1,000,000 hours.(100 years)
Raid-1 does not protect you from other types of losses such as viruses,
software errors,raid controller failure, operator error, or fire...etc.
For that, you need EXTERNAL backup.
If you have external backup, and can afford some recovery time, then you don't need raid-1.
Consider the merits of concentrating on a simple single windows-7 system.
download the w7 upgrade advisor to check for any issues:http://www.microsoft.com/downloads/details.aspx?familyid=1B544E90-7659-4BD9-9E51-2497C146AF15&displaylang=en