Using Windows 7 Professional 64bit, I set up a raid through computer management. It was my first RAID and incredibly easy to setup.
In case you don't know what a drive mirror or raid is—Basically, everything written to or deleted from one drive is done so to the other, so my data is backed up in case one HDD (hard drive) fails. This is called a drive "Mirror" also known as "RAID 1"
Since I already have a windows 7 system with room for spare drives, my total cost was $200—the cost of the drives themselves.
I wanted to see how fast this was and it turned out to be surprisingly fast for 1 user access as you'll see below. I also did a test for two users writing 1gb file at the same time which had a significant performance decrease.
The file size (1 Gigabyte) was a big test, so for most home users this performance hit wont be felt as much as it shows in here. I wanted to give it a decent test though. Generally speaking, most files are accessed fast enough that they'll be done transferring before others make more file server requests.
There's one incredibly huge problem with the built in Windows Software RAID though, if a drive fails, Windows doesn't let you know. I wish it would regularly check, but it doesn't so you should regularly go into computer management and make sure a drive isn't missing. There's a very long discussion about this on Microsoft Forums regarding this issue. If anyone knows some free or extremely cheap software that can regularly check or "take the blood pressure" of my Windows 7 Professional 64 bit hard drives, please let me know.
I'm currently considering a "FreeNAS" server now known as "NAS4Free" system. The first huge hurdle will be buying equipment that's compatible with Linux. The built in Windows RAID was sickeningly easy. *Shudders*
The software I used to perform these tests is called "LAN Speed Test (Lite) v1.3 (Free)" and can be downloaded for free here: http://www.totusoft.com/lanspeed.html. There are free and paid versions. I use the free, but may one day use the paid versions. Really easy and runs right from the executable—no install.