That's pretty odd. Raid architecture obviously requires more than one disk(RAID = redundant array of independant disks), but more than that, I believe there are two types of setups... hardware or software raid. Hardware raid is linux file system based, such that without a raid controller a windows computer can't read it. Software raid is different, and way more unstable. I would guess, given that you're running a notebook with one harddrive, if RAID is enabled in any shape or form it has to be software RAID, which I've never worked with... I'm not sure there's an actual answer to the question you have without someone having had the same problem which I can't find.
There's an argument that, if raid is on, disabling raid will ruin the sectors' arrangement, and your OS will need to be reinstalled, all data lost. But, that's because the sectors have all been spread out over several disks, emulating one large disk. Since you only have one, there's a possibility that when you disable raid, it will leave the organization intact, since it's really not supposed to be on for one disk and theoretically can't do anything anyways. Wish I could give you a more concrete answer, but from where I'm sitting, it might ruin your OS, but it might have 0 impact and actually fix your performance issue.
Setting the disks to non raid shouldn't wipe them, as far as I know, so if the disk is in a usable state after that(i.e. in a windows native file system, and as the sole system disk it has not had it's data striped with another drive) then I think there's a good chance that you will be okay. If you are very worried to try, and you are afraid of losing all of your stuff and for some reason can't back up critical data, you may want to look into getting some imaging software, and create an image of the drive before working with it. That way, if you manage to destroy all of your data, you can just throw the image back on the drive and it should resume normal operation(might need to reactivate some software though).
The only real hook I can see here is if you haven't thoroughly determined that there isn't a second harddrive in the laptop. It would need to be similar in size and type to the first, and if you haven't yet, it might be worth checking the bios hardware menu to see if it is registering another HDD. I've seen some pretty crazy hardware arrangements in laptops and netbooks, I would be suprised if there's a second harddrive hiding somewhere in there but it's certainly not impossible.