Register at mektek.net and start a thread to make this simpler. However you need to download the mektek's latest mech pack release which is 3.02a and then the 3.02b patch. Then you run the a file in your main directly called mekmatch and click yes which redirects where mechwarrior looks for servers. Then if you want this isn't required you download the HD patch which will make mercs look a little better. Make sure you run all the patching application as an administrator(right click on file, click properties, click on compatibility tab, and then select run as administrator).
These problems are very common with vista so be discouraged they can be dealt with.
Aurora Paradox