Ok, main PC with 120GB SSD has:
Win 7 Home installed. Hibernation turned off, page folder set to 2048. Crap load of apps + SP1 (backup of SP1 removed), 5GB of personal work folder on my desktop (well, on my SSD). The only symlinks I’ve created are to my personal folders, not to temp folders or other W7 stuff.
Fresh Win 7 Home (upgrade) install with SP1 & Drivers: 17.5 GB used. I thought before this was before turning off hibernation and setting page folder to 2048. Now, I’m not so sure. I need to take notes on this stuff next time I secure erase and reinstall W7 on my SSD.
At any, rate, SSD with W7 Home +SP1+Lots of Apps+5GB personal work folder –hibernation and + 2048 page folder = 26.7GB used.
My new ThinkPad with W7 Pro+SP1+Lots of Apps +3GB hibernation folder +4GB page folder and no personal folders = 33.7GB used. If I subtract the hibernation and page folders that my main PC doesn’t have that it has, then the used space is 26.6 GB, but that’s without the 5GB personal work folder that my SSD PC has, so the ThinkPad would be using 31.6 GB with my personal work folder dropped on it which ultimately leaves me with a 4.9GB delta between the ThinkPad (31.6 GB) and my main PC (26.7 GB). Browser caches, and temp folders flushed on both machines prior to comparison.
Basically what we’ve learned here is that I need to take notes…and beyond that, there may be a variance between full version and upgrade version installs of the same OS…maybe.
To the OP, you can use a tool like 7Customizer
http://www.msfn.org/board/topic/139077-7customizer-a-windows-7-customization-and-deployment-tool/ to shrink your install down to size. I haven’t used it, so beware and all that.