Hello, I've managed to get HL2 working in Server 2003 somehow (for now). It'll just lower the chances of the BAD_POOL_CALLER error: 1. Right-click HL2 in 'Play Games' 2. Click 'Properties' 3. Click 'Launch Options' 4. Add in '- heapsize <your RAM>' Good luck! *<your RAM> is your physical memory total in your task manager.