Only use Open Source Software!
If you would ONLY run Free Open Source Software on your Windows machine, there is the TTCS OSSWIN Free CD of 100 mature apps, you will have secure, safe, FREE software without any 'registration' problems, full and free support forums and usergroups, and the capability to actually contact the real authors if you ever encounter a glitch.
Whenever you try to contact proprietary software companies, since they are in it for the money, there is the strong possibility that they will mis-identify you as a thief, ala Microsoft's broken "Genuine Advantage" problem child ( 7day server outages, during Labor Day break!).
A major issue is that proprietary software is not well supported, most customers are used as 'beta' testers, and after the sale, there is little incentive for the company to support the product!
Then, too, the license disclaimer for proprietary software that you signed permits all of those folks to sell your Identity to the thieves in Russia or some former satellite nation of the USSR! Major credit data on millions of folks was sold to an identity theft ring in 2006!
Open Source software grows exponentially because it is user supported, and authors can even perish, and there are no restrictions about some other person contributing updates, and continuing the good work!