system builder friendly Windows version

[gort]

looking for (is there any ?) Windows version that would work with frequent hardware configuration changes, I want to just plug SSD with Windows into different systems and test the hardware

 

for now I have Windows 7 OEM, after replacing CPU it already says activation key invalid

[Snipergod87]

Nope.

 

[NumLock21]

If you're using it to test different hardware configurations, then just don't activate and do a clean install from time to time.