H_TeXMeX_H, I said I'd tell you how to keep a Windows box clean.....here ya go....
How to keep your Windows box secure
* Do not log on as an administrator. Create a limited account for yourself and USE IT religiously.
* When something doesn't work under your limited account, find out why it doesn't work and make the proper adjustments.
If in the rare case that you have a program that can't run under a limited account, make a shortcut that launches it under an admin account
* Install updates regularly
* Refrain from using Internet Explorer
* Run AV
* Run some sort of firewall (software/NAT router/etc) that blocks unsolicited connections from the internet
How to keep your Windows box stable
* Instead of bitching about them like a baby, learn how to troubleshoot windows kernel panics ("Blue screens")
Like linux and BSD and jsut about any other MODERN OS, OS crashes in Windows are almost allways caused by faulty hardware or drivers. If you are getting random reboots, do the following:
1) Log on as an admin
2) Right click on "My Computer"
3) Click on the "Advanced" tab
4) Click on settings by "Startup and recovery"
5) Uncheck the "Automatically Reboot" checkbox
Now, instead of rebooting, you computer will display a pretty blue screen with lots of informative information when it crashes. Use the information and Google to toubleshoot your problem. If your blue screen doesn't point to a specific driver, then you might have bad hardware. memtest86 is a good open source app for testing memory.
* Make sure all of the latest drivers for your hardware are installed.
* See above in the security section about not logging on as admin.
Buggy programs can sometimes do things by accident that will hose your system. Running them as a non admin will keep badly written programs from doing nasty things like corrupting your registry or deleting system files.
* Back Up your system state every once in awhile.
Sometimes when you install a new driver, the install doesn't go so well, or the driver just plain doesn't work and it will cause your computer to bluescreen on boot. backing up your system state using the built in backup utility before installing new drivers is a good way to revert back after a failed driver install. Safe mode should keep the dodgy driver from loading at boot. The neat thing about backing up your system state is that is creates a backup of your registry in "C:\WINDOWS\repair" that you can restore from the recovery console... (by copying the files over to "C:\WINDOWS\system32\config") so if you system get REALLY hosed and even safe mode doesn't work, you can still go into the recovery console and restore a known good copy of your registry.
[rant]
Don't bitch like a baby when something doesn't work under your limited account. I hear this all the time from Windows users when someone tells them to not log on as admin. "But so and so doesn't work unless I'm admin!!" the whiny botches say. Well tough shit. You run Windows, not OSX. You asked how to make your machine secure. If you don't like the answer then shut the fuck up and use linux or buy an Apple! Lots of things do not work in linux/unix under regular accounts without having to adjust permissions or set SUID bits. Linux users don't log on as root to do their emailing/porn-surfing in linux just because certain apps they use neet root or a SUID bit set...why should Windows users?[/rant]