chds

do the chd files that are on this site have to be converted to chd to run after downloading the files??

No! They stay as CHD... CHD are already compressed, chd stands for (Compressed Hunks of Data) typically need another ziped rom file to go with the CHD and be in the same directory. CHD on this site are multi RARed in split form.. you have to download each part and then uncompress them into one chd file using Winrar.

Sorry im new at this.  i didnt realize they had to be uncompressed.  thank you. 

Think of winrar in this context as a way to transport the file for downloading in smaller chunks... You download each part then use winrar to uncompress them into the CHD file for use... any part that is missing from the winrar set wont work... if it has five parts, you need to have all five parts to uncompress back to CHD.. Hope it helps...

yes it does thank you.