There is 100MB hidden system space created during Win7 installation. During my consequent (maybe the second, third installation of the system, I found there's only 70MB space left. However, some other's cases showed that their corresponding space could be over 80MB, say 86MB. I guess there's not much differences between these cases. I am using Win7 Pro ver, but I turned my system locale into China, Japan. What I mean is if switching locale may cause the difference of extra space occupation? -------------update--------- Well, I just format the hidden system partition during the GUI Win7 installation (but I set the partition to ACTIVE in DISKPART). Now the Disk Management shows that the hidden system partition has a 72 free space, a 2MB extra space was created. It seems that Win7 could write something into this hidden partition and the added file/info amounts to about 2MB. What are these files?
about 30 mbs. That partition is used to fix windows boot problems. No if you run into boot problems, you will need to boot from a Windows install CD and do the repairs