GParted says hard drive is "unallocated"

[Cipher1874]

Here's what gdisk gives me.

GPT fdisk (gdisk) version 0.8.1

Type device filename, or press <Enter> to exit: /dev/sda
Caution! After loading partitions, the CRC doesn't check out!
Warning! One or more CRCs don't match. You should repair the disk!

Partition table scan:
MBR: MBR only
BSD: not present
APM: not present
GPT: damaged

Found valid MBR and corrupt GPT. Which do you want to use? (Using the
GPT MAY permit recovery of GPT data.)
1 - MBR
2 - GPT
3 - Create blank GPT

Your answer:

How do I set the data as read-only? And does that require ubuntu to be installed, or is that still when it's running from the CD?

[oldfred]

gdisk has nothing to do with read only. Why are you wanting read only?

You have gpt partitioning so you do need to pick #2. If you pick number 3 you erase drive and #1 converts drive to MBR but booting then will not work.

I think you need the repairs for most applications to see drive.

[Cipher1874]

Oh, sorry, I meant the C: disk on Ubuntu.

Alright, after I pick that, where do I go from there?

[oldfred]

I do not understand where you are at. There is no c: disk in Ubuntu. C: is Windows.

[trusktr]

This problem happened to me after trying to clone a Windows 8 UEFI disk to a smaller disk. Maybe that's why he's referring to C