partitioning - The CRC for the main partition and back up partition table are invalid

I've been having problems with my HDD since I tried dual booting ubuntu 14.04 with windows 8.1. When I was installing from the ubuntu installer I was receiving "input/output error during write on /dev/sda".

I can't do anything in gdisk, it seems that both the main and the back up GPT header are corrupt. It seems that the back up header is unable to save whenever I do anything and try to write to the disk. At this point, I've already lost all my data, I don't have any of my windows partitions, and I just want to start fresh and be able to reinstall either windows or linux. Any help is greatly appreciated

When I try using fdisk:

$ sudo fdisk /dev/sda

I get "The backup GPT table is corrupt, but the primary appears OK, so that will be used."
I tried to use

g create a new empty GPT partition table

and

w write table to disk and exit

I get "failed to write disklabel: Input/output error"

v verify the partition table

I get

No errors detected.

Header version: 1.0

Using 0 out of 128 partitions.

A total of 1953525101 free sectors is available in 1 segment.

using gdisk:

$ sudo gdisk /dev/sda

I receive

Warning! Error 5 reading partition table for CRC check!

Warning! One or more CRCs don't match. You should repair the disk!

Partition table scan:

MBR: protective

BSD: not present

APM: not present

GPT: damaged

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Caution: Found protective or hybrid MBR and corrupt GPT. Using GPT, but disk
verification and recovery are STRONGLY recommended.

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when I enter v to verify my disk i get

Caution: The CRC for the backup partition table is invalid. This table may

be corrupt. This program will automatically create a new backup partition

table when you save your partitions.

Identified 1 problems!

I have tried loading back up and main gpt tables but no matter what I do, when I enter w to write table to disk and exit I receive this error:

Unable to save backup partition table! Perhaps the 'e' option on the experts'
menu will resolve this problem.

Warning! An error was reported when writing the partition table! This error

MIGHT be harmless, or the disk might be damaged! Checking it is advisable.