I have recently installed W7 Pro 64-bit but I'm still playing around with it. I understand that M$ recommends 20 GB for x64. I would like to give it a generous amount of room to work, but I don't want to go overboard. I have 3.5 GB of system memory but plan to upgrade to up to 4 or 6, so I don't think I'll be overly dependent on a swap file. Typically, I turn the Shadow Drive off and just use Acronis True Image to occasionally make images of the partition that holds the OS. I like to make several partitions in order to better organize my data. Videos, music, games, etc. I might decide to put "my documents" in a separate partition. I formatted my hard drive using the W7 setup DVD, but options were limited. Later when I went to shrink the drive I couldn't shrink it below 186 GB (on a 400 GB drive) because of the MFT. Unless someone here can show me otherwise, 186 GB for the OS seems excessive and wasteful. At this point I'm not looking for help on HOW to resize the partition. I just want to know what my goal should be. I don't have enough "real world" experience with W7 to know what it needs to run smooth, and it's not the kind of thing that's going to be easy to redo later on in time when all my data is in place on the hard drive. So what's a generous but not overkill size for the OS partition? Sorry if this question has been asked before. I tried to search on this term but I the net was too wide and I kept getting unrelated information. In that case, links or keywords for searches are appreciated.