End of Archive Error?

[Qfanvnaa]

Little bit off topic, but just have a question about this error I've been getting:

I have downloaded a file in 7 different RARs
Usually my default unzip program in UnRARX

When I try to unzip a RAR, I get a "Unexpected end of archive" error.

Basically, how do I combine these 7 RARs / extract them such that I dont get this error?

Thanks