Can’t boot in dos mode

I have used ME for a long time now, and I am satisfied with this “OS”. The problem bigin when I used Partition Magic 5.0 and moved and rezized some of my Linux/SWAP/Fat32 partitions.
Parition Magic could not execute the changes I made, because WinME would not boot in Dos mode. What can I do to solve this problem, do I have to boot from My floppy ?