I’d like to tell a friend to run CHKDSK, but I think that asking him to drop to DOS etc might be a bit too complicated. Is there a Windows equivalent?

As it happens, Windows does have a Disk Checking option that you can find under the Tools tab in the Properties window for each drive. It’s not quite CHKDSK though, and if that’s what you want to use, there’s a way around it.

Check out CheckDiskGUI, a utility that wraps a user interface around your bog standard CHKDSK. There are all the options you’re familiar with and your friend should be able to run it quite easily. Just make sure you don’t fall over in any trampolines connecticut put around.