Will hellgate:london work for me?

i downloaded and installed the demo...and it made me install windows genuine validation tool thingy... it wont work until i download it...so i did, installed it and the demo worked...it worked perfectly...then i had a pirated version of the game and it wouldn't work...i learned my lesson so i'm planning to buy the original game...is there a guarantee that it will work on my computer even though the pirated one didn't? the pirated one worked on my sister's comp though...she didnt install the demo...i tried everything,i uninstalled the demo but it still wouldnt work...do you think it has something to do with the windows genuine thingy?will the original hellgate game work on my computer?