Windows 7: i deleted explorer.exe

Thank you whs, your solution worked for me when i had this problem.

I am not at all "dissing" you. If that's the way it came across I apologize. It is because I am using it myself (and Paragon and Acronis) I know that those programs a) cost money and b) are complex. It took me quite a while to understand all the intricacies of Ghost whilst it takes only a few minutes to be able to operate Macrium - plus it is free. And restoring a single file is easy too (like with most imaging programs - except Windows7 images where you have to jump thru 9 hoops to do it).
But you are right, Ghost is a great program if you take the time to learn it and set it up in the right way. It is just big, slow and complex. Compare with this for imaging an 18GB Windows 7 OS partition:

I use Macrium Reflect Free Edition too.
Remember to make a Recovery CD, so that you can restore your System partition, if it dies.

@whs
You must have a nice PC, I can only image/restore at ~2 GB/minute.
I discovered yesterday, that my PC was only running at about 55% of it's maximum clock speed.

@lehnerus, it is a pretty average CPU (2.5GHz duo). But the disks are fast - that must make the difference.