Im fetching a local xml file using jQuery ajax through an html that i download from my site.
The problem is that each and every time the file gets downloaded, the user must right click on it -> properties -> unblock. Otherwise jquery ajax throws a “permission denied” error.
Is there any way to mark the file as trusted or something similar? Should i implement something on the serverside when downloading the file? Or add something on the client side in the saved html file? Thanks in advance.

The NTFS file system attache to this file a flag as unsafe. You can use one utility from Sysinternals called Streams to remove this flag. You can download the Streams from:
http://technet.microsoft.com/en-us/sysinternals/bb897440.aspx
Then using the Process class you can run the
streams -d <file.xml>command to remove this flag, after you have get the file. How to run it:The Streams are from MS site, so its official and credible source, and its just a utility that remove this flag from the file. I think that you can do your job.
Related:
https://superuser.com/questions/38476/this-file-came-from-another-computer-how-can-i-unblock-all-the-files-in-a
http://www.k9ivb.net/files/This%20file%20came%20from%20another%20computer%20and%20might%20be%20blocked.pdf