Problem with Counterstrike 1.3

We have a here a 23 units of PC, that have a Duron 750, 128MB of RAM, 32MD of Video ram 100Mbit of NIC, we used this for gaming like Counterstrike, Red Alert2, Batle Realms

In Counterstrike we used the 1.1 version it run's smoothly...co'z our problem is when we update it 1.3 every minute there is a computer that hangs.......That's my big question??????? Why the system hangs up in Counterstrike 1.3....is there a bug there????????Or it have some parameters that need to change....

Any ideaabout Counterstrike 1.3???????