I slipsteamed x64 SP1 into a plain retail Windows 7 x64. Are you sure you didn't make a x64/x86 disc?
Edit: I did remove the pre-installed songs, but I doubt they were over a gig.
I'm going to try re-running the program, maybe it was a glitch. The OS size the program reports is 3.85GB though. Not sure what it's doing to gain the extra size. I didn't even slipstream SP1.
and downloaded the x64 version. Then the RT7 2.6.
The plain Windows 7 image wasn't that large to begin with. Whats the size for your plain Windows 7 image?
The original size was 3.85GB. However, when I put the disk in and right click on it, it shows about 5.72GB. If I drag the files to my desktop from the DVD, it also shows 5.72GB.
This is what the program reports:
OS Name:Windows 7 HOMEPREMIUM
OS Description:Windows 7 HOMEPREMIUM
OS Size:3.85 GB
Language:English (United States)