Caviar Blue 1TB WD10EALS starting to have errors

I was using HD sentinel to check on the health status of my hard drive yesterday, and I noticed a bunch 197 Current Pending Sector Count errors. It went from 4-32 counts. I restarted my computer to have windows 7 loading, but it was close to impossible to open any programs or do anything. If I try anything it’ll freeze completely. Can I RMA my hard drive based because of this? If I can, what can I do to delete all my data on the HDD? Any specific progams to use to format the HDD?

Also it is stated '197 Current Pending Sector Count: Number of “weak” sectors waiting for reallocation. When the reallocation completed, this value may decrease.’
But on HD sentinel the health has dropped below 70% and I’m not sure is it still dropping. I’m not even sure what reallocation is or how it’ll affect my hard drive in the long run.

So anyone please give me a few opinion on what to do. Thank you.

Hello,

Backup and replace…