Windows 7 help
 

I just got a valid activation key from my school and i wonder if you can use that key for both windows 7 enterprise and pro. And i also wonder if i choose a 30 days trial, can i activate my windows after the 30 days has passed? And how many times can i use a cd key? =)

I believe that activation keys are tied to one specific version of Windows. So no, you [probably] can't use an Enterprise key on Pro.

You can choose a 30-day trial - just don't enter the key when you install Windows. It's also possible to dive into a setting somewhere (read: config file) and edit it to give you the maximum of 120 days.

Unless it's a site key, or for a specified number of users, you can use it once (that is, you can only have one version of Windows running on that key at any one time).

okey but if i choose a 30 trial will i be able to enter a key when the 30 days has run out?

I imagine so... but you don't really want to wait for 30 days - when it's up, the operating system loses all functionality. Basically, you'll have an OS installed that does nothing but take up space.