Microsoft and Amazon announced Windows License Mobility which allows enterprise license holders to migrate their licenses to Amazon’s EC2 instances. The program is currently running only as a pilot and Microsoft only allows the license to be used for Windows EC2 instances for a period of one year. After one year (if the program is not extended) the license will revert to a standard Windows Server license to be installed on a dedicated machine and EC2 pricing will revert to standard Windows EC2 rates.
The signup process is quite lengthy, and involves filling out registration forms, requesting Microsoft’s confirmation and then having Microsoft and Amazon countersigning the agreement. The process is unlikely to be completed in less than 10 days.
Windows Server Standard Edition entitles the holder to run a single EC2 instance, whereas the Datacenter and Enterprise editions allow for four EC2 instances. There is no distinction between the various EC2 instance sizes.
Once a user has been approved, pricing drops to same as the Linux EC2 instances (ie approximately 30% less than the standard Windows EC2 instances). Pricing is as below:
| Standard On-Demand Instances | Windows Pilot Usage | Windows Usage |
| Small (Default) | $0.085 per hour | $0.12 per hour |
| Large | $0.34 per hour | $0.48 per hour |
| Extra Large | $0.68 per hour | $0.96 per hour |
This offering is currently being limited to license holders based in the US.