Number one, trying to go from 3 to 1 pagefile pieces will net you zero performance gains. It is not worth any risk involved.
However, you can do it manually:
- Set to 'No paging file' and reboot
- Defrag the hard drive
- Set the page file back to system managed or custom size and reboot
The only pagefile change proven to give performance boost is to move it entirely to a partition on another drive, not another partition on the same drive as \Windows.
Lee