Help with daemons tools?

i decided to dowload all of the half life saga, so im using a program called daemons tools to emulate the discs of the games, the question is that im not sure if this program is all the time running on the backgroung, and its causing my sistem to lag, im using just a netbook with no disc drive (thats why i use daemon), it has a 1.7 dual processor and just 1gb of ram, is this program running all the time? now that i have the games installed, do i have to keep it, or i can unistal it now?