Win 7 -Seeking "Real world" recommendation for OS partition size

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.

Setting system partition's size is really a matter of preference. I'd recommend using at least 60 Gb if you plan to install software on this partition. Better 80 Gb.

What is your HDD's total size?

correction: I have 4GB of sys mem, not 3.5.

My HD is 400 GB. That was plenty for me when I was on XP. For XP (x86), I gave the OS partition 22GB but it rarely filled more than 7-8 Gbs. I try to put as much non-os data as I can on other partitions. I do this because I like to occasionally use True Image to restore the entire OS partition just to freshen it up.

60 Gb still seems high, but for peace of mind I could live with it. 186GB is outrageous. ( It's unfortunate that the W7 setup DVD didn't allow me more advanced options when I was formatting the drive prior to install. I know this and other forums offer workarounds for this.)

What's the reasoning behind why the OS would need 60-80 GB? Other than the Shadow Volume and swap file, why would it need so much room? I don't run a lot of gadgets or apps, but even if I did, that seems like a lot of space. Then again, I don't have much W7 experience and my understanding of the technology is limited.

Thanks for your advice.


Senior Member
you could keep the partition lower and put the swap file on a different hard drive or different partition.

Thanks guys. I decided to just make the partition 70Gb. I think it's overkill, but I'll still have enough room on the HD to do what I want.

I've got a new problem though. When I use the setup DVD to format the drive it only lets me to one partition. I go forward and install W7 normally but when I go to shrink the drive the smallest I can go is 186 GB. Insane.

So I used my win xp cd to boot and wipe away all the partitions. Then, I created one 70 partition and exited. Back in with W7 setup DVD. It sees the 70 partition and installs it just fine. At desktop I go to the manage hard drive section of the control panel. I'm confused. The primary partition is 70 and the rest is unallocated. From past experience, I thought I was supposed to designate which partition was the primary and which was the logical. Then I could make as many non-primary logical drives as I wanted. However, there's no option. I create one new partition and it's part of the primary. Any I create after that are labeled as logical drives. It might not matter if my partitions are primary or not, but my preference was to have only the partition with the OS be primary and the rest non-primary. Anyone know how to do this?

Also, when I first formatted the drive I noticed that W7 created some kind of system resource partition (about 100mb). When I started over and preformatted the partition for 70 GB, it didn't create the system resource partition. This worries me. Why didn't it create it?

Please help me clear up these issues. Thanks.

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