partition problems

hi I've installed a new 3,5"" HDD to my PC for storage purpose, working together with my current HDD. Because of other reasons, I clean re-installed windows 7 again. During the partition section, I allocated new partition to the new HDD. However, after clean re-installing the windows 7 on the OLD HDD, I ve found that there is a small partition which is 100MB (not created by me) appearing on the NEW HDD under disk management, stated to be reserved for system. I think windows 7 was installed on the OLD HDD while it automatically created small space for the system on the NEW HDD, which is something very odd to me. I don't want that. I 'd like to know what I can do now to make the NEW HDD a purely storage partition without hidden partition for another HDD.

Do I have to re-install everything again? In fact I don't really understand why, while the system was set to install on the one HDD, but it could create partition on another physical drive (HDD) by itself.

I don't think it makes sense, but it's the real truth happening


Excellent Member
Microsoft Community Contributor
Attaching a picture of your Disk Management Window is always helpful.

A Windows install in Legacy mode (MBR) will put the boot files on the primary drive as designated in the Bios. It will them place the OS on the drive you tell it to.

If your OS partition is on one drive and the Boot files are on the other, you can set the OS partition as active using Disk Management. Then disconnect the other drive and run a Startup Repair probably 3 times to restore the boot and the Recovery Options.

Then you can reinstall the other drive. Make sure the non-booting drive is set as secondary in the bios. If the system boots normally you can remove the active status from the 100 MB partition. Again, a snipping tool picture would be helpful in verifying your exact situation.


Extraordinary Member
This is a classic. If you have multiple disks, you have to disconnect All disks except the one where you are installing the OS.

The installer has the habit of grabbing the first disk it finds to place the system reserved partition. That little 100MB partition contains the bootmgr and is vital for your operation. If you delete it, your system will not boot.

The easy fix is to copy the bootmgr to the C partition:

There are more elaborate procedures, but the result is the same. You can also reinatall with that second disk physically disconnected.

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