I/o device error.... and realllly slooooooowwwwwwwwwwww

ok so my sister bought a 1tb wd passport looonng time ago and the warrenty is expired… but the problem is that sometime i get an i/o device error trying to transfer a big a file over to the passport and so i reformat it and it say it success but when ever i try to transfer like 2gb or more file onto the passport to slow down my whole computer sooooo much… and the transfer just freeze… please help (and i didnt know if your suppose to reformat the drive or not)

To confirm if the drive is working properly you can run an Extended Test running DLG:  How to test a drive for problems using Data Lifeguard Diagnostics for Windows 

ok im running the diagnostic soo if it fixes the problem ill click the star for u :smiley: ty for replying

well i ran the extended test and i got this: 

Model Number: WD My Passport 071A
Unit Serial Number: [Deleted]
Firmware Number: 2019
Capacity: 1000.18 GB
Test Result: FAIL
Test Error Code: 08-Too many bad sectors detected.
Test Time:

20:42:59, August 03, 2012

how do i fix this?