can i install windows phone 7 on HTC desire? I own a android phone, desire . I wish to install windows phone 7 on it .
 Can I do so ? and if the answer is yes, how ? 
Thanks
Nope you can't. Android phones are a bit "blocked" for other OSes to be run and installed on the device... By the way the first approach for this can be found at HD2 ToolBox and Hot Bootloader, which may help developers to build boot some other OSes on top of Android.

Different from the Windows Mobile era, that for example my HTC Touch Pro2 can run Android(fully featured) and Ubuntu(with some restrictions), not to mention al those OSes that have been ported to the HTC Leo(HD2).