Latest,
Exchanged my memory again to:
KINGSTON 4GB 1600MHz DDR3L Non-ECC CL11 SODIMM (KVR16LS11/4)
Still same problem! The only common thing with all my tries was the source of the windows ISO, the program used to burn and/or move to USB (Microsofts own program) and the computer I did it on - so I tried one more thing. I took one original MSDN Windows 7 DVD that I was just about to throw away......and IT WORKED.
I'm feeling a bit stupid at the moment - but at the same time I cannot stop thinking about what could have been wrong:
-ISO being faulty from MSDN, I doubt it but why not
-ISO getting faulty while downloading, I would presume the program would have some checksum to check it?
- "Windows 7 USB/DVD download tool" messing up the files when moving it to USB or DVD
Anyhow, thanks for your replies! Now time for some configuring!