For some reason i get mega lag when i play ns of +150. It dosent make much sense why it happens. I have scaned my computer many times for adware, and i have had ni improvement. I also get the same lag in counterstrike, but only those 2 mods. I use steam, which may be at fault. I can play other HL mods without any trouble at all, its just those 2 that give me trouble. Any ideas?

Open steam, go to settings, select the internet tab, change your speed to whatever yours is, this seems to be the cure in most cases...

make sure that no other games (eg DoD / CZ) are updating while you're playing - that is another common cause for lag problems that people don't notice because Steam by default will update official games without asking you