STD means Standard version, non activated. OEM means it will be activated by original manufacturer license of device. Windows 7 Ultimate – Standard / DAZ / OEM versions.Windows 7 Professional – Standard / DAZ / OEM versions.Windows 7 Home Premium – Standard / DAZ / OEM versions.This Windows 7 64bit (11in 1) iso September 2021 include: (just while making it bootable from rufus (provided in the archive), choose your target file system as MBR or GPT). While installing this you will not face any problem of GPT or MBR partition error. NET Framework 4.8 and All Important & Security Updates are pre-installed till September 2021. Windows 7 64bit September 2021 Update : This iso files has all September 2021 updates available till date. Latest version of windows 7 64bit with all September 2021 updates containing Home Premium, Pro, Ultimate and Enterprise variants.