Alright, this is a little guide on how to fix that.
First, you'll need to download Microsoft Visual C++
Link: http://www.microsoft.com/downloads/details.aspx?familyid=32bc1bee-a3f9-4c13-9c99-220b62a191ee&displaylang=en
Download and install that, then check if you can run the SoulMS Client.
If you can't run SoulMS. Then you'll need to download Microsoft .NET Framework 3.5
Link: http://www.microsoft.com/downloads/details.aspx?FamilyID=AB99342F-5D1A-413D-8319-81DA479AB0D7&displaylang=en
Download and install that as well. If it tells you that you need to download something while trying to install one of the programs, Google that program and simply download and install it.
This should help you get your SoulMS running if it has the error (0xc015002)