paging file.....Need Help

Please help
my pc has PIII processor800MHz ,128 mb RAM (64+added 64)
Hard Disk 40 GB (regular three basic Volumes/Drives C ,D & E)

[Drive C: 14 GB Free space 7 GB
Drive D: 11 GB Free space 9.5 GB
Drive E: 11 GB Free space 1.8 GB ]

i use multiple operating system
Windows XP has been installed , first on Drive C then on Drive D
[ It really Helps me when one system suffers with any problem]

i need to allocate maximum paging file size
especially to active operating system on Drive D

( i will definitely add 128 mb RAM later on )

so what maximum size i need to allocate for current 128 mb RAM
and in future for 256 mb RAM

PLEASE please Help

Thanks.

 

I normally let windows set the paging file but the rule is if you want to set it yourself 1.5 of your RAM. 128MB set file size 192 and 256*1.5 = 384

 

thanks for the info