hi, today I got this working after a lot of search.
read this doc
Adobe Flash Media Server
at Adobe Flash Media Server Configuration and Administration Guide / Configuring the server / Configuring content storage /Mapping Directories to
network drives
actually FMS is running as a local system account. So, change its log on account to one which has network access. Go to run-> services.msc.
open the properties for flash media server service & flash media administrator service and change the log on account.
after this it would probably start working for you also.