I have a Gigabyte slic modified bios which activated Win7 Pro 32 properly when I used a Dell OEM install dvd. Now I wanted to change to Win7 Pro 64 (ISO downloaded from microsoft so I assume its a retail version). After I install, I run slmgr with the GIGABYTE-GBT-2.1.XRM-MS file and slmgr reports a successful installation of license. However checking in control panel/system after a reboot reports that it hasn't activated and has 30 days left. I thought it might be related to it having a retail key originally and tried changing to a DELL OEM SLP key with slmgr but it wouldn't accept the key as valid (Does anyone have a GIGABYTE SLP key for Win 7 Pro?). Is it possible to do a OEM activation using a retail install ISO. Any suggestions on how I can get this working would be appreciated.