I have a Seagate internal hard disk drive. I recently opened up my laptop [Dell Inspiron N5010] [Warranty has expired], cleaned it and it worked normally after waking up from hibernation. However, when I restarted it, it stuck on windows loading screen, then tried to boot from Dell recovery partition but failed. It gave the error:

Windows has encounter a problem communicating with a device connected to your computer. 

This error can be caused by unplugging a removable storage device such as an external 
USB drive while the device is in use, or by faulty hardware such as a hard drive or 
CD-ROM drive that is failing. Make sure any removable storage is properly connected 
and then restart your computer 

If you continue to receive this error message, contact the hardware manufacturer. 

Status: 0xc00000e9 
Info: An unexpected I/O error has occurred. 

While cleaning, I had mistakenly touched the round silvery thing at the bottom of the HDD. I don't know whether this has caused the problem or not. Since I have Fedora also installed in the same HDD, I can boot from it but it shows weird read errors when I ask it to mount Windows partitions. The disk utility also says that the Hard Disk has many bad sectors and needs to be replaced.

I downloaded Seatools from Seagate website and used it. In the long test, I gave it permission to repair the first 100 errors which it did successfully. Now I am confused at what I should do.

Internal Hard Disk Costs: 
a.  Internal HDD 500GB Costs: Rs3518 
b.1 External HDD 500GB Costs: Rs3472 
b.2 External HDD 1TB Costs: Rs5500 
c.  Internal to External Converter Costs: Rs650 


I have the following options: 

(i) Buy an External HDD, backup my data. Try to repair bad sectors of HDD. Then two cases arise: 

(a) My Internal HDD gets repaired [almost] 

(b) My internal HDD doesn't get repaired. Then I need to buy another internal HDD and replace the damaged one. OR break the seal of the external one and put it inside my laptop as internal. Breaking the case involves risks. 

(ii) Buy a Internal HDD and an Internal to External Converter Case [Not very reliable], backup my data. Try to repair bad sectors of HDD. Then two cases arise: 

    (a) My Internal HDD gets repaired [almost] 

    (b) My internal HDD doesn't get repaired. Then I need to just put in the new internal HDD I just bought. 

Experts, please guide me as to what will be the most VFM option? Also, if a HDD is failing, is it that I shouldn't read from it too otherwise there is a chance of other sectors failing? What I mean is, is it wrong to read from the HDD without taking backup first?