Zebra MC92 window CE 7 downgrade to 6.5

Hello Everyone

 

The company I work for just purchased a Zebra MC92 to use in the warehouse. But I just discovered that the ERP system work only on windows CE Version 6.5.  Is there a way to downgrade from version 7 to 6.5? Zebra technical people sent me the file the run to downgrade 92N0w65LenUP005511.zip but when I copied it and extracted and run the StartUpdLdr.exe its giving an error  Unable to import Library AYGSHELL.dll ! Program will exit. Hope someone can help.