Looking for a tool that can tell me when my hard drives are expected to die. Can anyone recommend a (preferably) free one?
I'd thoroughly recommend HDTune - it has a benchmarking capability, access to SMART information and other device information, and a low-level surface scan (to detect bad sectors etc)
You need a SMART monitor, a program that displays the health statistics of the hard drives.
GSmartControl runs on Windows 7 and is free.
Hard Disk Sentinel works for me.
Also you can try HDDLife. It's quite useful tool for server monitoring. You can get for free only trial on offical site, but you can google it and find some patched version on some public torrent tracker.