OEM Partition

Question

I cannot assign a drive letter to OEM Partition. When I right click the OEM partition in Disk Management, all I get is Help! I think it needs to be labeled as D:

Thank you

My computer: Studio XPS Desktop 435T/9000 64-bit

speedstep · Accepted Answer

64 bit windows will have a 100 meg partition at the front of the drive. Then a 10 Gig partition then the rest of the drive.

The ACTUAL partition order is the 100 meg reserved then the 10 gig recovery then the rest of the drive.

The Recovery is usually labeled recovery and the OS is labled OS.

The Drive letter assigned to the 3RD partition is C:

Replacing the drive or totally reformatting will still assign the 100meg partition then the rest of the drive.

There will not be any opportunity to do anything to the 100 meg partition.

New Partition Format for Bootable Hard Disks

A partition is a contiguous space of storage on a physical or logical disk that functions as though it were a physically separate disk. Partitions are visible to the system firmware and the installed operating system. Access to a partition is controlled by the system firmware and the operating system that is currently active.

For 64-bit Windows, bootable hard drives must be partitioned using the GPT mechanism defined in EFI 1.0. GPT is also the default partitioning scheme used by 64-bit Windows for all non-removable storage media.

Microsoft does not support EFI on 32-bit platforms, and by extension, does not allow booting from GPT partitions.

The 100MB volume is labeled as System Reserved with NTFS file system, and System, Active, Primary partition attribute with no drive letter in Disk Management. The 100 MB system partition is used primarily as BitLocker partition for BitLocker encryption. Additionally, it also holds the Windows Recovery Environment (WinRE) and boot files with boot manager for booting up the computer for troubleshooting when there is no Windows installation DVD disc on hand.

osprey4 · Answer

Hi Jkitc, If you are referring to the Dell recovery partition, my suggestion would be to leave it alone. It should not be assigned a drive letter.

jkitc · Answer

Thank you for the reply. In the past it has been labeled as D:. In fact one of Dell's support person said that it must be labeled as D:. In computer management it is described as having 100% free space, and it think that is because of having no drive letter.

Please understand that I am not disagreeing with you, but just sharing my experience, so I don't have the definitive answer.

osprey4 · Answer

Do you have Vista or Win 7? Do you see the partition labeled RECOVERY in disk management? It should be about 15GB, NTFS.

jkitc · Answer

I have Windows 7 64-bit.  As far as the partitions, first I have the OEM Partition 47 MB, next I have the RECOVERY Partition 9.12 GB and then OS (C:)

Tom Green · Answer

Hello jkitc

The OEM is DellUtility that contains the diagnostics for your machine.

It should NOT have a drive letter. You get to it when you boot computer

and press F-12 and inter the Utility. The RECOVERY partition the 9.12 GB

usually has the D drive letter. Hope this helps.

Tom

osprey4 · Answer

My recovery partition does not have a drive letter.

Chris Waters · Answer

My Dell Latitude E6400 laptop, running Windows 7 64-bit has a 250 GB HDD with the following three partitions:

1 - OEM Partition (102 MB)

2 - RECOVERY (D:) (2 GB)

3 - C: (230.79 GB)

When I purchased this laptop three years ago, it came with Vista 32-bit installed (go figure). I immediately used my own media to install Windows 7 64-bit (formatting the drive in the process). I don't recall doing any customization during the Windows 7 installation. With that said, how can this drive's current partitions be reconciled with the information documented earlier in this thread? I have the OEM Partition; however, the RECOVERY partition is only 2 GB -- not 10 GB.

BTW, this drive is failing. I'll be receiving a replacement drive from Dell tomorrow. My uncertainty as to how best prepare the replacement drive is what led me to this thread. I appreciate any suggestions!

FYI: I have a Windows Home Server environment -- which includes a system restore tool. My WHS backups include both the RECOVERY and C: drive partitions. I believe this tool will restore the data to both partitions; however, I'm unsure how the tool does that. I'm also unsure how to create the OEM Partition.

Chris Waters · Answer

Thanks! Are you suggesting that the partition labeled "RECOVERY" is a leftover from Vista installed at the factory? I probably saw that partition when I installed Windows 7 64-bit -- but ignored it and left it as-is. It sounds as though I shouldn't bother trying to create a recovery partition on the replacement drive. Do you concur?

What about the (presumably Dell-provided) 102 MB partition labeled "OEM Partition"? What does that contain and how can I re-create it on the replacement drive?

speedstep · Answer

With 64 bit windows clean install It will create a 100 meg partition at the start of the drive. This is not done by dell its a microsoft thing. OEM or Retail 64 bit windows will do this.

The 100MB partition is a system partition and contains boot files. Disk Manager will not allow you to remove this partition because removing this partition could cause the system to not boot.

speedstep · Answer

Vista Recovery Does not work after WINDOWS 7 is installed over it.

Chris Waters · Answer

So in my scenario (already having a 102 MB partition labeled "OEM Partition" -- installed by Dell, no doubt -- and a 2 GB partition labeled "RECOVERY" -- likely a leftover of the original Vista installation), the Windows 7 64-bit installer didn't create the 100 MB system partition; it created just the 230.79 GB partition and labeled it C:. But if it doesn't have the system partition with the boot files, I wonder how the system boots?

I appreciate your suggestion as to how to proceed with the replacement drive. Should I let the Windows 7 64-bit installer create the 100 MB system partition...and dedicate the balance to the "C: drive" partition? Doing so would result in no 102 MB "OEM Partition"; what do I lose if I don't create that?

Chris Waters · Answer

My earlier response was a bit wordy; let me try again: Do you recommend that I create the 'OEM Partition' on my new/replacement drive? If so, how I do that?

speedstep · Answer

The upgrade from Vista to WIN7 broke this. There is not a way for end users to redo this.

Chris Waters · Answer

OK, I installed the replacement drive and then used WHS's Restore PC function to restore the system from backup. Now I have just one partition on the drive, consuming all of the space on the drive. I do *not* have a 10 GB 'boot partition'; nevertheless, the system is working well.

I still have a "Diagnostics" option on the boot menu; it's apparent it from running it, however, that it is not the full diagnostics. For instance, the extensive hard drive test (which conclusively determined to me and to Dell technical support that the original drive was failing) is missing. Can I restore that additional diagnostic functionality? If not, is there an equivalent diagnostic tool in the Downloads section?

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OEM Partition

New Partition Format for Bootable Hard Disks

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