i have half life 1 (i think) and it came with half life: deathmatch, and team fortress clasic. i had steam installed for something else and i just installed HL1 and i can't play it couse it tries to activate with steam, i figure no problem. well i was wrong. it says the validation code was used already, witch is wrong couse i got this as a present for x-mas and it was sealed. so any ideas what i could do?