For most users, the official is the definitive way to play. However, for those dedicated to preserving the original 1.0.0.0 release, the process remains possible: mount the disc image, cancel the online activation, apply a crack or keygen, and install the cumulative patches (1.0.1.0 through 1.0.4.0) to stabilize the experience. Always ensure you are abiding by your local software copyright laws and be wary of malware associated with unofficial key generators. Drive fast, drive safe, and watch out for spike strips.
If you have a valid serial number but are receiving errors, it is likely due to the following:
If you own a physical copy and have lost your manual, you do not need to look for a random serial number online.
If you want, I can:
Many legacy activation servers for 2010 physical discs are no longer maintained, causing valid retail keys to return errors or fail authentication on modern Windows operating systems.