Boot Camp Assistant cannot be used.

I try to install a windows partition with Boot Camp. But it can't be opened, with an alert pop up as:

"Boot Camp Assistant cannot be used.
You must update your system software before using this setup assistant."

I checked the software update and it is all up to date....

Any help, please?

what version of OS X are you using?

10.6.1

Oh it is solved.

For ppl who have same problem, make sure your HDD is in a SINGLE partition!