I need my code modified to correct some error I recieve.

General information for the business: File sharing website
Kind of development: Customization of existing program
Description of requirements/functionality: I require my current code modified to remove some errors. This is part of a much larger project. If you know what you are doing then this will take no more than an hour, however I don't have the time to investigate fully.

The code at present copies information from one computer to a Sql server machine (using WCF) and then inserts it into the filestream.

My code runs into problems when:

- multiple clients from the same location try to copy information (needs to work with an ASP.NET client)
- Trying to copy information to the same location the second time.

I need my code modified so it can do the above successfully.

Unfortunately, there is no test environment.
Specific technologies required: WCF, Sql, CSharp, C#, SqlFileStream API
OS requirements: Windows
Extra notes: There is no test environment. The code sent is all I can give. A few small errors will be okay since I can change the code myself.
Ideally I would like this completed within a few days, however if you find there are issues then the timeline is flexible.