windows 7 - Why does Windows7 create two partitions?

I installed Windows7 Ultimate from scratch, and it warns that it might create a 100MB partition before creating a second one where the real stuff lives. This makes imaging more complicated.

# fdisk -lu

Disk /dev/sda: 320.1 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xf1f75308

  Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048      206847      102400    7  HPFS/NTFS
Partition 1 does not end on cylinder boundary.
/dev/sda2          206848    30722047    15257600    7  HPFS/NTFS
/dev/sda3       172908544   254828543    40960000   83  Linux

Does someone know why Windows7 needs two partitions, and whether it's possible to have a single partition?

I'm also interested to know if any steps are required before imaging Windows7 (sysrep, etc.) where the image will be reinstalled on the same host (own test machine).

Thanks.

Answer

The second 100mb partition is your boot sector, plus recovery options. You should NOT delete this; however, you can avoid the creation of this partition if you format your drive using something other than the Windows Setup before installing Windows.

P.S. You can assign a drive letter to this partition in Disk Management and see what's on it if you're interested.