i´ve downloaded a tar-file with mirc but it wasn´t completed so i used resume to download the rest. but now when i want to untar it it shows only the parts i downloaded the first time but not the ones i downloaded the second time. does anyone know how to repair the file?

I would suggest you delete the file and re-download it.

You could download again or run a search for the exact download at a different website.
(Edited because of a few spelling errors).