About four days ago, my Toshiba Satellite A505 laptop provided an imminent hard drive failure warning. I did a backup. Since, it continues to function but it's "running" constantly. I suppose the hard drive is spinning or the fan is running? I don't recall it doing that constantly.

So, I wonder what to do. I note that I can get a hard drive for $90. Is it somehow possible to just transfer the entire contents of the current hard drive to the new one?

I admit I have done no maintenance on this laptop and it's about two years old. A 500GB drive, I've only used 70GB. 4GB RAM, Intel Core 2 Duo.

Should I defrag or do anything else? Getting a new computer is a hassle, I wish I could fix this.