lost space on hard disk after reset

Solution
Okay, thanks for that.

It shows that there is 527 GB of "unallocated space" on that hard disk (the shaded area). That's where your "missing space" is.
You need to right-click on that shaded area and choose "Create new simple volume".
When the volume has been created, right-click on it again and choose "Format".

When formatting is complete you will have a new drive-letter in Windows Explorer for that new volume. You can store files on it or install applications on it, just like you do on the C: drive.

If Windows won't let you do anything with that shaded area (menu options are greyed out), you will have to boot your computer from a partition management disc which is free from here...
Okay, thanks for that.

It shows that there is 527 GB of "unallocated space" on that hard disk (the shaded area). That's where your "missing space" is.
You need to right-click on that shaded area and choose "Create new simple volume".
When the volume has been created, right-click on it again and choose "Format".

When formatting is complete you will have a new drive-letter in Windows Explorer for that new volume. You can store files on it or install applications on it, just like you do on the C: drive.

If Windows won't let you do anything with that shaded area (menu options are greyed out), you will have to boot your computer from a partition management disc which is free from here:
http://www.partitionwizard.com/partition-wizard-bootable-cd.html

That boot disc allows you to bypass Windows restrictions because Windows won't be running.
 
Solution