I have a desktop application that needs to upload/download images to/from service computer over TCP Protocol.
At first, I stored images in file system, but I need to
Which version of SQL server? Version 2008 adds FILESTREAM which is specifically designed for this purpose. FILESTREAM data can be located on disk which makes it very fast to access.
If this is not an option, you could look into creating a separate filegroup for your image data (to give you the most flexibility when partitioning your data) and use the varbinary(max) or image data types.
A SQL guru will probably chime in with better info.