Thanks for your advice and keeping my spirit up...
Now I fell into another trouble..
This time I partitioned my hdd into 3. first osx, then rest two msdos ( because I needed a partition for exchange data between OSes.)
As usual I first installed Windows vista on 2nd partition msdos. It was booting fine. After finishing vista setup, I installed ML via USB into the OSX partition. I installed clover using boot0ss Now I can boot ML fine but not to vista.
Clover is showing the two os in menu ML and Boot windows from Legacy 3. If I select Vista I see a cube-like icon for sometime then blank screen.
Can u tell where I went wrong?