Hard Disk Crash 303 ERROR - NEED HELP PLEASE !!!!!!!!!!!!

Hi Guys,

I am using windows 7 64 bit on my hp pavillion g6 laptop (g6 - 1118tx model) and the warranty is expired . Well I ve got 2 problems , please read the whole problem and provide some solution.

• Around a week back my Laptop got struck(edit - windows 7 os got struck .. hangs .. watever) so i have restarted it , but when i did it showed some error message "windows was unable to start your system" something like that .. I tried safe mode,installing windows again and even recovery disks that i have got but all of them did not work out.
  
  so i have run diagnosis on hard disk and the test result is a 303 ERROR , which turned out to be a hard disk crash when i googled about it.. But i need to back up my data , so did some research and used UBUNTU live cd to back up data , which worked fine and i am able to back up all the drives except the C drive (may be C drive got crashed)
  
  I thought i need to buy a new hard again but i saw install option in ubuntu live cd and ubuntu got installed and in the processing of installing I FORMATTED 2 drives as EXT PARTITIONS (do remember this point).. After that I installed windows 7 on another drive (not C drive) which worked but now the system is very very very slow , you cant imagine how slow it is , takes 30 mins to copy 500 mb file, 5 mins to open my computer..

So now my problem is ...

1. Should I replace my hard disk ??, because when i asked friend of mine in service center he said its better to replace, because even though its working now he said it may crash again in future and who knows the whole data might be lost
2. If I dont want to replace, can you guys provide any solution to speed up my system ??
3. Do you remember the point about partitioning 2 drives as EXT in ubuntu (refer above) .. well those 2 drives i am unable to format in windows 7 .. its shown as free disk space but I am unable to delete the volume (delete option is not highlighted ) not i am able to create a new volume , it says "There is not enough space available to do this operation"..

Please help me if you know any of the solutions and also suggestions

First, I'm not quite sure what you mean by your computer was struck. But, from reading your explanations, it does appear to be a bad hard drive. But, before buying a new one, download the bootable version of your hard drive manufacturer's diagnostic program and run the extended test. If it is working at all you can normally get some if not all your data off with a live Linux distro like you did, and if Windows can see the drive, you can copy/paste from the recovery console. If your drive works at all you can also try a recovery program like Recuva.
You can also clean, format a hard drive during windows installation to resolve your other problem. SSD / HDD : Optimize for Windows Reinstallation
This method will work even if you cancel out and do not install Windows, but I suspect you may have startup issues with Windows and Linux installed together. This may help with that issue.
MBR - Restore Windows 7 Master Boot Record