I still don't understand why not just install correct version of windows 7 and use Daz loader to install correct certificate and key for your dell machines. And wait to see what happens when windows 10 goes RTM and see if they update. Then if needed you can use the OEM:COA keys.
Well... Then explain to me why the x64 didn't activate with the key and the x32 activated right away. I'm now looking for an other x64 ISO to try again. I'll let you know how it goes.
Because you screwed something up. The key stuck on the outside of the computer would work with either x32 or x64 versions of the proper edition, if done correctly. Again, there is more than one type of Win7 oem key, and you are far better off using the oem:slp method, which would not involve the coa key stuck on the outside of the computer. Activation can be implemented manually by installing a certificate and oem:slp key, or using Daz loader to do it automatically. Also, at this point, it has been established that even loader activated Win7 can be upgraded to Win10 and get permanent activation.
Hooray, the other ISO worked without any problems. I don't think I screwed something up 5-10 times in a row on two different computers. The other x64 ISO just wouldn't take the key whereas the x32 ISO did so immediately.