Problem solved :-D

Prob 1: transload files larger than 2 GB?
Solution: Edit the upload.php file and changed the limit from 1024 MB to any size you want.

Prob 2: rar/unrar problem?

Solution: first CHMOD the file "unrar" in rar folder inside the leech to "777"
Then download latest Rar files from rarlab,extract it in your pc,upload the "rar_statics" file to "rar folder" of your leech and rename the "rar_statics" to "rar" and CHMOD the "rar" to "777"


My Problem is solved that way.

Thanks to cowboyup910 for his cordial help.