Originally Posted by ollie_fool

You need to uninstall the beta via add/remove programmes to be able to play regular pr again, after that the origional folder will work. Also make sure the folder is caleed "pr" or no servers will show up in the list.

What we did with vBF2 to be able to play 1.41 and 1.5 without uninstalling anything, should work in this case as well. Just copy the whole bf2 folder, rename it to something other than the original, say bf1.41 and apply the patch.
Now you have two folders, one with the original name, this one is the patched and the second is the renamed, this is the un-patched.

If you want to play with the original, just rename the folders. The bf2 (or PR in this case) shortcut will always launch the one with the unchanged folder name.

HERE is the link to the post explaining it in more detail.

If you, like me, have multiple mods installed, but only want to make a backup of one, than you dont have to copy all subfolders in the mods folder, just the one you want to leave un-patched.

For example, when i tried the 1.5 patch, i copied my whole bf2 install, except the poe2 and pr subfolders under mods. In this case, i would leave out bf2 and poe2 folder, copying only pr and than patching that copy to the new version. When i would want to run the new version, i would just rename that copy to Battlefield 2 (or whatever you original install folder is), and rename the original to something else.

Just remember, your desktop shortcut always points to the original bf install if you haven't changed it.

For the "invalid client_shaders.zip" error, try deleting the contents of your cache folder (not the folder itself!) located at c:\Documents and Settings\your username here\Documents\Battlefield 2\