While I no longer own a Windows computer, I did use that operating system from 1996 to 2004 and I picked up a few standard practices that will help keep Windows running smoothly and quickly without having to resort to all sorts of different adware and virus scanners in order to keep it working.  The first step is to start with as clean an install of Windows as you can get, if you’re going to install a retail copy of Windows, go with a clean install rather than an upgrade.  If you have a computer with Windows pre-installed you will likely have several megabytes of junk-ware programs that need to be completely removed before you really get started.  Once the shovel-ware has been removed, you will want to run your system updates to get the latest patches and fixes.  Of course, during all of this you want to make sure that your computer is behind a hardware firewall in order to keep it safe from malicious software.  Now that you have a trial-software-free system that is up to date, it is time to start installing your programs.  Only install the programs that you need and trust, avoid programs like RealPlayer and MusicMatch as they will slow down the system and annoy you with pop ups asking you to upgrade.  Definitely avoid things like memory monitors and shareware that promises to make your computer run faster as they never do.  You will need an antivirus program, go with a lightweight one that isn’t full of feature bloat.  When I ran Windows I ran AVG, I’m sure there are better versions out now but back then it was a very lightweight product.  Now that you’ve got your software installed, it is time to use the computer.  Because of the massive number of viruses that depend on Outlook Express, I would avoid that program altogether - I just used webmail rather than an email manager on the PC.  Basic safe practices always apply, don’t open attachments from anyone you don’t know, don’t download programs off the internet from companies you don’t trust 100 percent, and never ever ever use Internet Explorer for anything.  Finally, download a copy of a live Linux distro and burn a copy to a CD, use this if you must go to sites that are of a less than savory nature.  Using these basics, I was able to keep my Windows XP install running relatively problem free for 3 years without getting any viruses.