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#21
Dell will probably include an applications disk, a drivers disk, or both. You may need to use the drivers disk to install peripherals such as a printer.
If you reinstall Windows, using your own Ultimate disk, that may void your warranty.
You should talk to Dell about that on the phone before you purchase.
Anyway, why would you want to waste your own Ultimate disk license when Dell gives you Windows free?
I have no idea what you mean by "Jailbreaking and stuff".