Comments - sagesh

What did you replace? Have you tried maxexcloo's suggestion?

Yes, you need Half-Life 2: Episode Two on Steam. Did you even read the description? "Research and Development is a puzzle-centric mod for Half-Life 2: Episode Two featuring an unarmed player but plenty of violent mayhem."

Well I think the mod still works fine, and it works with steampipe version of HL2 as long as you fix the gameinfo.txt by following maxexcloo's advice (you can see it here in the comments).

I just finished this mod, and it's really AWESOME! I would love to play a part II if there is any :P

Ah, I forgot to sign in to the site, non-members can't see my comment unless it's approved or they sign up :p

If your game crashed after you open gta-vcs.exe, try turning off DEP for gta-vc.exe and gta_sa.exe on GTA VCS and GTA SA's directory. You can do it by right clicking Computer and then click properties. On the left, click Advanced system settings. And then in the Advanced tab, click on Settings.. button on the Performance section. Click the Data Execution Prevention tab and click Add.. then locate both executable files on your GTA VCS+GTA SA's directory. Hope that helps!

Mirror link:
Atomicgamer.com