Possible errors that you may encounter:
1)sgen.exe error : If you get sgen error while dealing with web services, you should change Generate Serialization Assembly option to Off. It is found in solution properties>Build tag.
2)File directory permission error: Most servers do not allow programs to create folders or files without permission. In our case, web service creates a file in TEMP directory because web service is used without publishing it. We need to allow all users to modify this folder.(WINDOWS>TEMP)
3)web.config error : The web.config that we copied may cause error in IIS. Changing appropriate lines fixes the problem. In my case web.extentions caused an error in config. I just deleted these lines because i didnt use any extention components in my web service.