how do i use multi-part roms?

[NeonArmy]

well the title says it all i have a game with 20 different files and dont know how to use it :S

[DB81397]

This may seem useless, but I picked the biggest file with Crash Team Racing. It has four files, including the .IMG. Also, what system are you emulating (I specialize in GBA, but I can TRY to help with PS1 emulators).

[Lukong]

well the title says it all i have a game with 20 different files and dont know how to use it :S

It sounds like you got them in ".rar" or ".7z.001" you should use 7zip to extract them in order to get the rom, its actually one rom split into many parts to make it easier to download.

The rom is compressed and needs to be put together and extracted [Open].

[Roms]

Lukong is right for part files. If it's a part zipped archive with *.part in the end, use winrar. If it's numbers like the example lukong mentioned, use 7zip. Or do you mean bin cdi?