ISO time format.

YYYY-MM-DDTHH:MM:SSZ

(4 digit year)-(2 digit month)-(2 digit day)T(2 digit hour):(2 digit minutes):(2 digit seconds)Z

T - wallclock time starts here

Z - zulu time, or UTC time

Microsoft has opened its own software archive of downloadable Windows .iso installation images. If you have an original retail product key but don't have the installation media, you can download a copy of Windows 7 to rebuild. Please note that this might not work on OEM systems, which bundle their own clusters of drivers and have unique registration codes.