How to convert

Can someone help me know how to convert 'cbh' files to 'pgn' ?

With ChessBase.

1.Open the original file, cbh in your case here, with ChessBase and copy it (Go to Games, Select All, and Copy)

2.Create a New Database in whatever different format you want, pgn in your case here.

3.Open your New Database in your new format, pgn in your case here, and paste the games that you copied from the original database into the new database. The games that you pasted into the new database will now appear in the new database in the format of the new database, pgn in your case here.

ChessBase, Fritz, Chess Assistant and Aquarium can do it.

The only free program I'm aware of is Kvetka. It's quite buggy (in particular with large databases) but it might be worth a try. Open a CBH file in Kvetka, choose "Save", "Save games as.." from the menu and select PGN as target format. This should do it.

thank you :)