1. Does that appear when U try to reinstall Windows? (I mean, on the setup screen)
2.Or you are just trying to format some drive with the right click>format?
If 1. , then do the following:
-boot again from cd, and press R key.
Type your installation number
(usually 1 )
type password
(if U don't have any, just press Enter)
Now U can format by typing this:
format X:\ /Q
(X stands for the drive letter of the drive you want to format)
Do not use other letters , just the one of the drive U want to format!!!
(Q stands for quick format)
Other options are available for format type, like NTFS,FAT,FAT32,etc.
You can see more options by typing:
/?
If 2. ,you want to format the drive within Windows, then try in Computer management in Control panel, or try an utility from the internet, to do it for you.