Yep as long as you make sure that it is turned on.... we've heard varying reports that sometimes, for some reason it is off.
Right click the start button and choose run and in the run dialog box type
rstrui.exe
hit enter or click OK
To check to see if it's on or off and how much space it has allocated and is using....
Right click the start button and choose System
In the left column select System protection
Your drives should be listed and it should report if it is on or off for a particular drive.
Select a drive and then....
You can click the configure button to check your settings, adjust the mas usage, delete all restore points, etc., etc.