I've just downloaded Tor browser package for Windows XP 64bit but when I try to make it work it gives me the above message. Can anyone tell me why it is doing this and what I can do to make it work?
Well, I had this problem until about 3 minutes ago. I had my AV (Anti-Virus) on, turned it off, and -ta-da!- fixed. Some more mainstream/better anti-viruses may allow Tor, Sophos for example. (The AV that blocked my Tor was Webroot SecureAnywhere, which I use more for the tools and Website Screening more than AV itself) Hope this works for you!
To whitelist Tor Browser: Open Webroot SecureAnywhere - Identity Protection Settings (gear) - Application Protection (tab). Find any Tor apps (e.g., firefox.exe in \tor browser\browser directory) and select "protect". My Tor firefox.exe had "deny" selected. This fixed it for me.
I changed the name of TorBrowser/Browser/firefox.exe to firefox2.exe and it started. If you do this test change it back or updates won't work.
As mentioned above the antivirus will stop it from running. My test makes me conclude that because the exe file is named the same, an antivirus will notice that it is opening from a different source then stop it from running.
- What Jake Nonnemaker wrote is the solution for Webroot. For me the item on the list was "mozglue.dll in d:\tor browser\browser" moving it from Deny to Protect fixed it.