I was working on a Windows 2008 DC and getting it ready to Prep the domain for a Windows 2008 R2 DC. I wasn’t on-site so I had no access to the a DVD Drive but I had the iso downloaded. I extracted the files and copied the Adprep folder over to my Windows 2008 32bit DC well when I ran adprep /forestprep I got the warning wrong version of OS 32bit versus 64 bit. OK now what to do as there is no 32bit version of Windows 2008 R2 RTM. I went over my possibilities and went back and looked at the apdrep folder a little closer and what I found as there is a adprep32.exe in the folder so I ran this on my Windows 2008 32bit DC and away Prepping the forest and domain went. I now could bring in my Windows 2008 R2 DC to the domain.
Til Later just Roger