Yes i want to change key, not ID.
Its simple as using CheatPack
You must put OFP:Cold War Crisis CD to your CD-ROM.
then (for backup purposes) You must change Your Operation Flashpoint DIR to Operation Flashpoint-1 dir. Then start install new OFP in the same dir Operation Flashpoint. When You install it, You can delete instalation and rename Operation Flashpoint-1 to Operation Flashpoint again.
But in REGISTRY You will have NEW serial and new oryginal ID. You can save it to REG file and install another copy of OFP in the same way, save another ID to REG file. And later change Your id only clicking on different REG files. I have 8 ID in that system. All from oryginall OFP serials purchased on eBay.de for 2euro