The brand, model, and operating system of your PDA, the operating system of your computer, and what software you are using would all be instrumental in determining the cause of the problem, as well as the solution. Also, any additional information, such as error messages, would be helpful. If you are using Windows XP, that's the first place I'd look...check the files/folders, and make sure that they are not encrypted, are not marked private, and do not have permissions set. (Basically, the file must be accessable by even guests on the computer if you wish your PDA to have access to it, for it doesn't support those security measures.
I am able to connect to my network on my PDA and browse thru the folders and files on the three PCs I have on the network. Problem I am having is I am unable to use the file directly from the network. For example I cannot play an MP3 file that is located on my deskop PC in my PDA unless I copy and paste that file to the PDA's main Memory or SD card. The only way to get it to play is by cut/copy&paste the file to the PDAs main memory or SD card. That goes for any file music/pictures/word etc...
I can use files between PCs remotely and figured that should work the same way for the PDA. Any Suggestions?