Here are some tips to keep your wallet secure:
ALWAYS use antivirus software (The paid AV is better than free. AVG seems to work best for me, there is a free version if needed)
ALWAYS use a firewall (Most AV software includes this, make sure it does. Also, make sure you have a hardware firewall.)
NEVER download from an untrusted source
NEVER turn off User Account Control on Windows Vista/Windows 7
NEVER turn off your AV/Firewall unless you really have to for a video game, web server, etc.
ASK yourself these questions before you download anything:
1) Do I know what this program does?
2) Is there any chance this program contains a virus?
3) Is the file name misspelled or does it look suspicious?
4) How many people downloaded it, and were there any bad reports about it?
KNOW that every file can possibly have a virus hidden in it
KNOW that no virus scanner is 100% effective
KNOW that a virus can NOT harm you unless you open it
MAKE backups of your wallet file (PM me if you do not know how, I'll tell you.)
ENCRYPT your wallet with a very strong password of AT LEAST 10 words
BE AWARE that there can also be viruses for MAC OS and LINUX (and other operating systems)
RESEARCH all programs. No reviews or information? Don't download. Ask around first.
I hope my post keeps the community well informed.