Is it possible to create difference permissions for subfolders and files in a network shared?
Users are allow to modify files but not modify any folder in the network shared.
If possible, users can modify files but not delete them.
Typically the answer is no - the file will inherit permissions from the folder it lives within.
However, you may be able to use account permissions to overwrite other permissions but this is too complicated to explain over a post.
If I understand the question, yes. You can do it both ways too. Properties are inherited from folder to folder, so if the root of the folder path has 'Read & Execute' everything will. You can both tack on and subtract permissions though. I run Windows 7, but it should be similar on XP.
1) Right click on the file, go to 'Properties'.
4a) From here you can use "Add" and "Edit" to tack on new permissions, and it's possible to seperate the modify/delete permissions (which is why I'm going through advanced).
4b) If you want to subtract permissions, you need to uncheck "Include inheritable permissions from this object's parent". This will turn off the trickle-down effect of permissions and this file (or folder) will have it's own permissions. If it is a folder, every file in it will follow the same trickle-down rules. It's reccomended to select 'Add' when you uncheck it. This will keep it's current permissions and let you modify them. 'Remove' will just remove every permissions and you will not be able to edit this file/folder again if you accept the changes without adding yourself back on.
Hope that helps!