HELP! How to restore the original space in the external drive that's been used for windows recovery

Hey there. I don’t know if I’m even asking for something possible. I bought a WD external HD three weeks ago, and have been using it for only one week. My pc (Dell) has recently been blue screening and then I went for system recoverying. I saw that I could creat a recovery disc, and then I used the WD hard drive for it. The original space was 1TB, and now it’s just the size of the disc, or course (about 31GB). Is there a way to undo this disc formatation, and regain the original space of the HD? 


That sounds like the drive has been repartitioned/formatted and you’re now only seeing a small partition on it.

Personally for situations like this, I like  Partition Wizard, which is a free (for home use) partition manager and toolkit which can view, change/resize and reformat partitions. Just be careful when using it, as of course if you get it wrong you can do more harm than good (double-check before committing any changes made, and ensure you’re doing them on the correct drive).

But used with care it’s a flexible and powerful tool - I often use it with my Raspberry Pi to restore SD cards which have been partitioned up for use there (Linux format dual partition). The program has good documentation, which I’d recommend you read. That said you can use it to view and analyse what state your drive is currently in before actively doing anything to it anyway.