Reinstalling Windows without re-registering Delphi

The .slip files used for registration info are in C:\ProgramData, in either the CodeGear or Embarcadero folders depending on which version of the IDE you're using.

I've successfully copied the files from these folders to a thumb drive and moved them to a new computer. Note that part of the registration information is the local computer name, so in order to work on a different machine (or a clean Windows install on the same machine) the computer name needs to stay the same. Just name the computer the same, copy the .slip files to the same location on the new machine, and then install Delphi/RAD Studio.

To be on the safe side, I always copy the entire folder (including all subfolders and their contents) to make sure I've gotten everything the IDE needs.

I had a similar problem when renaming my Windows 10 computer. Apparently the license is bound to the computer name. I had to re-register Delphi after renaming my computer but failed because of the limit of my license key. Solution was renaming back my computer and renaming C:\ProgramData\Embarcadero\.cgb_license.corrupted and C:\ProgramData\Embarcadero\.licenses\.cg_license.corrupted to files without the .corrupted as suffix. My licence slip file was C:\ProgramData\Embarcadero\.2016_2.#############.slip.