3TB Seagate capacity reduced to 750GB after failed Win 7 install

Hello

I tried installing 64bit Win 7 Ultimate on mirrored 3TB Seagate HDD using a Digitus RAID card and failed. After the failed attempt, I disconnected the HDD and plugged the primary HDD to an on-board SATA connector only to find its capacity reduced to 750 GB. Windows Preinstallation Environment shows the same size and running clean produced no effect.

Something odd I noticed after running diskpart is that no matter how many drive is connected to onboard SATA, it only shows the 750 GB and the PC name is MINWINPC.

I`m completely stuck with this and cannot figure any solution. Please anyone help me restore the original 3TB size.

Looking forward to replies.

Could you please have a look at it from disk management and post a screenshot?

Start - Control Panel - Administrative Tools - Computer Management - Disk Management. (or write "disk management" in the Start searchbox)

how to post screenshots in this forum

Thanks for the reply. Disk Management displayed the free space as Unkown Space with the correct capacity, so I zero-filled the hard drives and the drive capacity showed up correctly in the Windows 7 setup menu.

Regards,

D

The free version of Active KillDisk did the job on this occasion.

yeah, was suspecting that it did something weird with partitions. Theoretically, any decent third-party partition tool could have done the trick as well without fully erasing the disk.
Good to know that i's ok now.

Something odd has happened. Because I couldn`t build a RAID array using Intel Rapid Storage Technology after successfully installing Windows on a single HDD, I enabled RAID in the up-to-date BIOS and tried reinstalling Windows 7 on the RAID but failed. So I quick-formatted the HDD and used the MiniTool home edition to repartition it and found one partition with a capacity of about 2.7 TB to install Windows 7 on but the installation stopped just as it was attempting to configure Windows at the last stage.

I`m not sure if there is an issue with installing Windows 7 on a RAID array. Has someone succeeded in installing Windows 7 on a RAID array using an Intel Desktop Board?

Myth busted. The trick was to install the Intel Raid Driver F6 upon initiating the Windows install by choosing Driver in Windows Setup. Windows 7 Set Up does not load the driver for the Intel Desktop Board even after you have specified RAID in BIOS and created a RAID array.