Hi , regarding your primary system as you have so much ram memory space I suggest investigate using a ram drive (a system app) of say 1-2 GB and configure as page file , this will speed up some tasks as paging i/o will be via fast ram memory rather than relatively slow non-volatile storage - as usual will not suit all computers and usage but worth experimenting particularly if you upgrade to a SSD as the system storage
Regarding your XP Windows computer , seems you need some work there , mainly apps like Sygate firewall and System Explorer to figure out what is happening , but maybe also hardware so whether is worthwhile depends upon your task resource requirements and enthusiasm and/or dedicated requirements like paranoid mode banking etc
Just a few thoughts while I await the fair maiden in distress...