Windows 7: Back-up question

Hi

I'm a Mac user with no idea about Windows, but trying to help out my wife with her laptop, which is running Windows 7. I want to set up a back-up system for her so she can do regular back-ups and would appreciate advice on the best way to do this.

I had a quick look round the Windows7 OS and see that there is a back-up function already on there. Is this any good or would it be better to download/purchase some separate back-up software? If so can anyone recommend a particular software?

My other question is - if I want to back-up her entire computer (applications, system files, settings etc, etc) it would help to know how many GB is currently being used, that way I know how big an external hard drive to use. How do I find this out? Is there a way to find out the number of GB that is currently being used on the internal hard drive?

Cheers
John

I use Windows backup, & norton ghost v15, for System images, Data Backup

System Image Recovery
Backup Complete Computer - Create an Image Backup
Restore Backup User and System Files

To see how many GB you have on each Hd, go to My Computer.

If you want plenty of headaches, you can try the built in Windows7 facilities. If you want something easy and reliable and fast, use this: Imaging with free Macrium