If you're having trouble installing or connecting using the new 1.0.0.9 Half-Life/TeamFortress Classic releases, perhaps one of the following pair of tips sent along buy readers will help. Here the first one from ExsMediocre:

A lot of people are having problems connecting to 1009 FinalTFC. The 1009 TFC LAN patch installed a client.dll under tfc/cl_dlls dir. this file is not used or overwritten with the 1009 Final patch. If this file is still in your TFC dir you get an error about conflicting client.dlls and it will not allow the connection. The simple fix is just to delete this dll. Everyone including server operators need to remove this dll.

Even uninstalling HL first and then reinstalling does not fix this unless you delete the HL dir before reinstalling.

And there's this, from JB:

Problem : Error in setup, incorrect language settings when installing the 1.0.0.8->1.0.0.9 patch with Lan Party TFC patch already installed.

Fix : Change the ShortTitle entry in the sierra.inf file from "HALFLIFELAN" to "HALFLIFE"