The priciple is the same except you can't run in DOS, and this limits the programs you can use. I'm a little out of date, but I use Acronis Trueimage for disk-to-disk backups, which can image a hard disk under WinXP without a re-start. I can also recover from scratch using a boot CD, and select individual files or complete system.
My backup disk is removable, and I always pop the drive out when I've finished so no nasty viruses can get at my lovely clean image file.
Whatever you use, make sure you test it by doing a restore. An untested backup solution ain't no good.