I'm new to this forum but wanted to share my experience with a bad sector on a 1 TB drive after installing Windows 8 Pro. Of course I had not backed up my system for over 12 months and failed to set the cool new storage spaces up and did not create a Windows 8 recovery disk. Basically made every mistake possible.

Original problem: Windows 8 stopped loading
Attempted solutions:
Ran diagnositic utility on hard drive and found bad sector error.
(Shift+F8) Windows 8 will not boot into Restore Options and Auto Repair Fails.

Since my system was originally Windows 7 Home I ordered and installed a new drive
Loaded Windows 7 and received the Windows 7 boot menu
Attempted to boot to command prompt and access Windows 8 drive. Received CRC drive error.
Highlighted windows 8 OS and pressed F8
Selected Repair System
Original repair took a good 30 minutes seemed like a Windows 7 repair
Ran repair again F8 from the OS menu
Windows 8 Repair screen appeared and allowed me access to the command prompt option
Typed in the bad drive letter and it responded without prior CRC drive error
Ran chkdsk /r
It is repairing my drive as I type 10 thousand of 50 thousand files and 3 repairs complete.

I will check in later...

I hope this and be helpful for others in this situation. Needless to say if this works my past sins will be forgiven and I can take steps to prevent repeating them.

8PainsMe (Trevor)