WinRumor is reporting that Microsoft has started sending early access invitation of Windows 8 pre-build to OEMs via their Microsoft Connect program. The newly launched program named “Windows 8 and Server vNext Pre-Release Program” provides download access to Windows 8 build 7971.0.110324-1900 to selected OEM partners via personalized access links which look like http://connect.microsoft.com/site1094/InvitationUse.aspx?ProgramID=5474&InvitationID=XXX-XXXX-XXXX where XXX-XXXX-XXXX is the unique invitation code. A fresh set of complete step-by-step installation screenshots (posted after the jump) of Windows 8 also confirms the news.