My computer keeps locking up when my daughter plays zoo tycoon 2 but only when she adds water to the build. She can play it all day if she doesn’t add water, but as soon as she adds water it will freeze within 1 or 2 minutes. I have done some research and it seems to be a problem with the Radeon 8500 card but I find no mention of how to fix it. Here is what I have done: I have a Radeon 8500 Series AGP Video Card. I downloaded the Microsoft Net Framework 2.0 and installed. I then downloaded the Catalyst Control Center 6.5 WIN XP Version and installed. I have gone to the game website and downloaded and installed the latest updates for the game. My specs are as follows: RADEON 8500 SERIES AGP (0X514C), Internal DAC(400MHz), Approx Total Memory: 128 MB, Current Display Mode: 1024 x 768 (32 bix) (60Hz) Main Driver: ati2dvag.dll, version 6.14.0010.6614, date 5/3/2006, DDI Version: 9 (or higher) I have updated my audio sound card drivers to Realtek AC97 Audio, driver is ALCXWDM.sys. Version 5.10.0000.6150 date 7/21/06. Operating System: Windows XP Professional (5.1 Build 2600) BIOS: Award Modular BIOS v6.00pg Processor: Inter Pentium 4 CPU 2.800GHz (2 CPUs) Memory: 1024MB RAM DirectX Version: DirectX 9.0c

There are newer graphics drivers available (6.6). You could try those. Also, I would increase your display refresh rate to 75hz. I don't know if that will help but it can't do any harm to try! P4 3.0 HT 800mhz FSB Asrock P4I65G M/B 2 x 512mb Kingston Value DDR 400 Dual Channel 80GB Diamond max9 SATA 160GB Diamond max10 SATA Club3D GeForce6600 256mb SumVision P4 450W PSU

Catalyst v6.5 is as good as it gets for the Radeon 8500. Catalyst v6.6 & v6.7 don't support Radeon models under 9500.

6.7 already. Thay sure bang those CCC's out thick and fast! P4 3.0 HT 800mhz FSB Asrock P4I65G M/B 2 x 512mb Kingston Value DDR 400 Dual Channel 80GB Diamond max9 SATA 160GB Diamond max10 SATA Club3D GeForce6600 256mb SumVision P4 450W PSU

"I downloaded the Microsoft Net Framework 2.0 and installed." have you tried the older version MS Net Framework 1.1 ? if not, try it and see if that fix.