Clean install as normal. Your data will be perfectly safe.
When going to do the clean install, you want to have your RAID controller
driver ready on a floppy, usb stick, dvd, cd or anything that is not connected to the RAID controller you're running.
If you're installing to a completely new drive not attached to the RAID, no
driver will be necessary upon installing Windows. You can then install the
driver in the device manager at desktop or use the installer .exe if it has one.
If you install to the same drive/partition with Windows currently on it, the installer will place all of your existing files in Windows.old folder at root.
You can then go in it once at desktop and copy/paste user account folders (or parts of)....things like that....or perhaps better, set everything up again manually because you'll have a clean install and anything not working right will not carry over to the new install.
Like for instance, you can copy just the Mozilla settings folder over to the new install. Or just the Winamp one..etc...at your choice.