I am checking the hard drive on my new Lenovo T400 laptop, where Windows 7 has been installed.

System Information of Windows 7 says there are three partitions 1.17 GB, 221.95 GB and 9.77 GB, but there are only two drives: C: of 221.95 GB and Q: of 9.77 GB.

Disk Management reports there are three volumes: Lenovo_Recovery(Q:) of 9.77 GB, SYSTEM_DRV of 1.17GB and Windows7_OS(C:) of 221.95 GB. All of three are simple layout, basic type and NTFS. Plus SYSTEM_DRV has status as healthy (SYstem, Active, Primary Partition), Lenovo_Recovery(Q:) is healthy(Primary Partition) and Windows7_OS(C:) is healthy (Boot, Page File, Crash Dump, Primary Partition).

My questions are:

(1) What are the difference between the three concepts "partition", "drive" reported by System Information and "volume" reported by Disk Management? They seem similar but not quite same. At least drives do not include SYSTEM_DRV, but partitions and volumes do.

(2) what is the volumn SYSTEM_DRV for? why it is not shown up in drives, only in partition and volumns?

Thanks and regards!


(1) Report of System Information about drives:

Drive C:
Description Local Fixed Disk
Compressed No
File System NTFS
Size 221.95 GB (238,313,005,056 bytes)
Free Space 202.36 GB (217,280,110,592 bytes)
Volume Name Windows7_OS
Volume Serial Number CC3B4EF0

Drive E:
Description CD-ROM Disc

Drive Q:
Description Local Fixed Disk
Compressed No
File System NTFS
Size 9.77 GB (10,485,755,904 bytes)
Free Space 3.28 GB (3,519,356,928 bytes)
Volume Name Lenovo_Recovery
Volume Serial Number B63E336A

(2) A screen shot of my disk management alt text

  • 1
    OK, you have one phsyical disk (hard drive) and three volumes, which might also be called partitions or logical drives. There's probably a technical reason for calling them volumes but IMHO it's semantic. Whatever terminolgy you're used to and "grew up" with is OK as long as you understand that a logical drive, parition, or volume describe essentially the same thing: a logical structure on a physical disk for the file system. – joeqwerty Nov 19 '09 at 4:20
  • 1
    Correction, you have three volumes (partitions): SYSTEM_DRV, WINDOWS7_OS, and Lenovo_Recovery. Two of these are logical drives that have been assigned drive letters: C and Q. So that's the difference: a volume or partition define a structure on the hard drive onto which you can create logical drives. You can have volumes or partituions without logical drives, as in your case with the SYSTEM_DRV volume. The volume or partiion marked as the System, Active volume is the volume that contains the boot files and is the volume that the OS boots from. – joeqwerty Nov 19 '09 at 4:27
  • Thanks joeqwerty! What's the difference between boot volume and active volume? I thought OS boots from Windows7_OS(C:) (Boot, Page File, Crash Dump, Primary Partition). – Tim Nov 19 '09 at 5:15
  • In Windows parlance, the boot volume is the volume where the operating system files are and the system volume is the volume where the boot files are. It seems opposite to logic, but that's the way it is. The active volume is the volume the computer will look for the boot code on when it boots up and is the volume where the boot files need to be. – joeqwerty Nov 19 '09 at 12:41

A hard drive is a physical device (disk). A partition and a volume are essentially the same thing: a logical structure on the physical disk for the file system. The system drive is where the OS boot files are located (Boot folder, bootmgr, etc.). The system drive doesn't show up in the hard drives because it's not a hard drive, it's a volume (partition).

Also, you'll notice in Disk Management that the hard drives are listed as Disk 0, Disk 1, etc. and the volume structure (layout) of each disk is listed to the right of each disk in the lower pane.

| improve this answer | |
  • Thanks! You mean a hard drive is a physical disk? Then how come there are two hard drives C: and Q: on my single hard disk? – Tim Nov 19 '09 at 3:15
  • You said in your second sentence that there are two hard drives: C and Q. Can you post an image of the Disk Management console lower pane? – joeqwerty Nov 19 '09 at 3:21
  • I just added the picture in the original post. – Tim Nov 19 '09 at 4:00
  • Volumn is used in Disk Management, while drive is used in System Information. – Tim Nov 19 '09 at 4:03
  • Sorry I should have say "drive" instead of "hard drive" in my original post. I meant to ask the difference between "drive", "partition" and "volumn". – Tim Nov 19 '09 at 4:08

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