You will not be able to maintain your current partitions.
Perhaps this will allow you to better understand what needs to be done http://www.mpspartners.com/2013/10/how-to-convert-windows-7-on-mbrbios-to-gptuefi/
This is assuming that your BIOS is full...
Perhaps this will allow you to better understand what needs to be done http://www.mpspartners.com/2013/10/how-to-convert-windows-7-on-mbrbios-to-gptuefi/
This is assuming that your BIOS is full...