What a nightmare. You may already know about this, but there's a free firewall you can download which really does deliver the goods. It was personally recommended to me, and I've had it on both computers for about 2 years and am very satisfied with it, as are various people whom I've told about it. Of course the company has "professional" versions which are for sale and are higher spec, but the one I have works well and doesn't have any bad side effects as far as I can see. They are at www.zonelabs.com, and you need to sort of hunt around for the free version, which is listed on the right hand side of the page about half way down, in a column of links ("ZoneAlarm Free"). That will then take you to a second page: go to the bottom and look out on the left for "Basic Zone Alarm" which is the free one. Click on that link which takes you to another page, a column-by-column comparison of the free version with their two "pro" ones (which if course will do more, but cost). If you want the free one, click the red "download" bar at the bottom of the left-hand column, which I will try to make a blue clicky of at the end of this post, which will skip all the preliminary stages. But really, it might be worth going in the "long" route and taking a look at what's on offer. Anyway, for the free one try clicking this:

BASIC ZONE ALARM