Thanks for the quick reply =)
I'm using McAfee, so its not an AVG problem. When I go into the .techniclauncher folder, the .jar file there doesn't work, I get a window saying that it can't be run. That is the only file in that folder. Not sure what you mean by a .net problem, and I don't know what I could do about it if it's a Java issue, as I only updated my Java software yesterday.