is there a way to identify what type of windows you have from the license number alone?
As the licence number is found on the W7 packaging which is plainly labeled, the only reason for identifying the version from key would be, if someone got hold of a key by duvious means and then tries to match it to a version.
Anyone that purchased it would know which it was.
If you have a genuine and legal key, you could contact Microsoft and explain the reason you need to know.
A lot of these keys that have been sold on the net have been blocked by Microsoft.