If change to read only have two way
1. You use windows exploring right click-> properties -> read only, if someone want to change they must clear readonly on properties
2. If you are admin of network you can limit member can access you files
My suggestion would be to save the drawings that you want viewed but not disturbed, would be to save them as a dwf file and let people view them inside a browser with whip. They will still be able to zoom turn layers on and off, and even cut and paste portions of a drawing into Power Point Presentation if they so desire. All this with out ever messing with the original drawing.
On a network drive, set the share to read only, then the files cannot be written over. For added security, make the riles read only on the network drive. To do this, Place all of the drawings in a single folder or on a drive by themselves. Then right click on the folder or drive and select sharing, then select "shared as" and enter a name. Then select read only. You will not need to supply a password since you will want everyone to be able to read the files. Now, open the folder select all of the files, then check the properties and check the "read-only" box. If you place the files on a drive with other files that people need to access, then make sure the root directory is shared as read only as well. You could always make a subdirectory read-write access without the drive read only status being compromised.
