Reliable backup software for Windows 7?

[classic35mm]

I am looking for a good backup program for Windows 7 Pro (64 bit). I recently upgraded from Windows XP Pro SP3. On that OS, I used HP SimpleSave software for my backups. HP SimpleSave did one full backup the first time I installed it, and after that, it would backup changed files every time my computer was idle for 5 minutes. And as this article notes, "The backup is simply the duplicate of the original files, making restoring very fast and easy." I liked HP SimpleSave's simplicity.

 

I doubt that HP SimpleSave is natively compatible with Windows 7 -- and even if it is, I'm not even sure where to get it (except from the original external hard drive).

 

What is good, reliable backup software for Windows 7? I'm particularly looking for software that will backup modified files every time my computer is idle for a certain length of time. Sort of a pseudo-continuous incremental backup.

 

Thanks so much for your time.