Shrink Windows partition with PM8. SP2??

I have just accquired a brand new Compaq Presario 8800SE.
I am almost determined to shrink the windows XP partition from 100 GB to 80 GB using Symantec PartitionMagic 8.0 . The new unallocated space I will use for three more FAT16 2 GB logical units, and maybe something else.
I am also determined to install Service Pack 2 from CD before or after repartition.
There is another primary partition of 4 GB, that contains the ‘Compaq System Restore’, software made by SoftThink. Maybe this package gets bewildered, when PM8 changes the Master Boot Record. I won’t touch that partition anyway. Maybe it becomes useless.

Have your say.