No, you won't harm anything
For future reference, any time you don't know whether or not it's safe to delete files or folders just rename them. If there is no problem after a boot or two, it's safe to delete them. And btw, in my opinion the BEST form of backup is to use disk imaging software on a regular basis - especially if you have a second HD (internal OR external). The best of breed is Acronis True Image, but it's not free. The best free alternative is Macrium Reflect.