1. Open Start -> Run... 
2. type diskmgmt.msc and press enter 
3. right click on the partitin you want to format (where the leter and size is)
4. select 'Delete Partition...' and confirm 
5. right mose button in the same place and select 'Create partition' 
6. select primary partition 
6. select size, file forma, disk leter, label etc should be all right if you leave defaults. 
7. click ok 

This will recreat the partition and format it in proper way. Helped me and will help to most of you if you have problem with MBR.