Snafu replacing internal harddrive

My harddrive is old and slow thus was about to replace.

My mac is the late 2008 macbook- silver unibody.
It had been working fine until I restarted it after backing up and now won't start up even in safe mode. I ran disk utility and it says that the drive is not repairable.

Last night I partitioned my external hard drive and erased all my back ups. I now have two time machine backups from yesterday as well as a clone that I made last night using superduper on a separate partition. I backed up overnight which took much longer than it ever had previously. I'm using USB 3 cable that came with my external harddrive but my computer is has USB 2 ports which never seemed to matter before but not sure if that has anything to do with the booting problem. My external harddrive is a WD My book for mac. I was trying to boot from the clone when this problem all started. When booting from clone it gets about half way through the process with the apple logo on top of the progress bar and then just freezes for hours.

I'm a bit resistant to take out the harddrive without trying to boot from the external . I didn't get a chance to check to see if everything was on there and working the way I wanted. Additionally my plan was to use the clone to transfer to my new harddrive and now i dont know how that wil work. With my time machine back up and the clone I think its likely I can transfer the majority of my data but was just curious if any one has idea of why my external won't boot or why i'm having trouble even starting up the internal harddrive after trying to boot from the external.
Is there a way I can make sure that my external is partioned correctly and that I have a full time machine back up with the machine currently not starting up?
At this point whats the best way to replace the harddrive?

You didn't mention what OS your computer is running. But if it's running OS 10.7 or newer…try booting into the Recovery Partition…by pressing command + r on reboot.

Then launch Disk Utility…and try repairing the disk…and maybe the permissions too.

- Nick

running yosemite. doesn't seem to want to boot in recovery mode. again being held up about 50% through the start up

ANy other ideas of why I can't boot into recovery mode now. I have a relatively new external hard drive. I reformatted it yesterday in plans of removing the internal drive and replacing. I have one partition with a super duper copy and one with a time machine copy so in theory I have two good back ups.

when the computer stopped restarting and would start into safe mode. I tried running disk utility a few times. Mostly the computer got hung up on starting up but one time i got in there and it said it was unrepairable so i just removed the old drive and put in a new solid state. My plan was just to get in there and partition the new drive and then try to get the macos yosemite off the back ups and either fully restore the drive to the old one or just copy things over. I have not been able to start up the machine when connected to the external what so ever. Wheras earlier this morning i could get into recovery mode I now cannot.

Update:

Put back in the original hard drive and got it to boot in recovery mode. Disk utility could not repair drive saying it was corrupt. I repaired some permissions on the back up disk which I created that bootable drive the day before in my plan to replace the original internal harddrive which I wasn't really having problems with other than it was old and a bit slow. I then tried to boot to that drive again hoping that those problems in the external copy was what was causing it not to boot.


I would love to get on my computer and be able to check to make sure my backups are mostly in order but the problem is this whole harddrive problem started when I decided to check to see if my new carbon copy of my harddrive was bootable. I do believe I saw that my hard drive appeared to be copied correctly but I'm hesitant to erase the harddrive not knowing what is on the external and if its all ok.

what i consider my options are:

1. trying to use a disk utility such as tech tool pro to repair the original harddrive. I'm not sure even how to do that now that these apps don't come with bootable CD disks.
2. try to erase the old harddrive and reinstall OS and hopefully restore from my carbon copied harddrive or my time machine back up. I tried restoring from time machine back up and not working. I'm a bit confused why but it seems like my computer is having trouble even getting to the external harddrive to restore. so far that hasn't worked. I've had the harddrive about 6 mos (it was replaced from one that failed within a year of me purchasing) I've never had problems backing up files on there but never really had to restore from it so this would be a first.
Any thoughts ?