Why has a new hard drive with the name “System Reserved (Z:)” appeared on my PC?

Rajeev Dandu May 2, 2012

I have a pen drive. Usually there is no problem when I plug it in. But now a new hard drive is appearing on my with the name “System Reserved (Z:)” and it’s empty of files but shows that 70.3MB is free of 99.9 MB.

After this happened, my Windows OS began to give me an error that says a change has occurred to the system and I need to reinstall Windows. Is this related to the mysterious hard drive? How can I resolve this?

    May 4, 2012 at 4:28 pm

    Hello, this could also happen if the system reserve partition is set to active. The system reserve is a 100 Mb partition without a letter as mentioned before. It stores the shadow copies for your system and it helps with backups of your system. You should be find with removing the letter attached to it.

  2. Bruce Epper
    May 2, 2012 at 4:32 am

    The System Reserved partition you are seeing is required by Win7 to boot properly. It is not empty of files but the files it contains are hidden system files (aka superhidden files). Normally it is not assigned a drive letter. There may be some software you ran from the pendrive or that was auto-run from it that assigned the drive letter. This is also the most likely cause of the error message you are seeing.

    You can remove the drive letter by going into Disk Managment (Win+R to get the Run... dialog, then type "diskmgmt.msc" without the quotes and pressing Enter), right-click on the Z: drive and select "Change Drive Letter and Paths..." from the menu. In the resulting dialog box, click on the Remove button. Click Yes in the confirmation dialog. Close all remaining open windows.

    • Ray
      May 2, 2012 at 10:18 pm

      I can confirm what Bruce said. His fix will work fine. You may (depending on the vendor of your PC) also find another partition, in the case of Dell, it's called the DellUtility which contains recovery tools.

      Both can be eliminated IF YOU KNOW WHAT YOU ARE DOING, but it is tricky. I say this only because others have tried to delete them and rendered their systems inoperative and unbootable.

      Beyond taking the drive letter off, Do not play with them unless you know what you are doing, and have valid backups of All of them.