cheat engine problem

ok so im having a problem with my cheat engine. whenever i try to check the process box, the whole thing highlight s but the box doesn't check so the cheat doesn't activate. I'm thinking this might have to do with me using Windows ME because i just came back from cousins house and it worked fine doing the exact same thing on his Windows XP computer. Anyone have any suggestions on whats wrong and how to fix it? Help is much appreciated.

u need to select the process u wana use to inject the code :-P go to the top left of cheat engine window check there and a list with all process will apear, select the process scriptvessel.exe (i think u wana us for this) after that it will ask u if u wana keep the current adress list tell yes! and then u can checl the boxes.

ok I've done all of that except check the box. i can click on it but then the box doesn't check and my whole computer lags for about 5 seconds
Does anyone know if cheat engine 3.5 doesn't work on Windows ME or sumthing?