Windows 7 is a big deal, many people in the tech industry believe it will be the catalyst for the next tech boom in hardware sales. Could be, Windows 7 is a great OS. Staying secure in Windows 7 however still requires users to be careful. If you upgrade to Windows 7 one of the first things I recommend most users do is go to UAC in their start search click on "Change User Account Control Settings" . Once the UAC window appears use the new slider interface to move your security settings all the way to the top to "Always Notify Me", the most secure setting you can have. The reason is obvious the UAC is there for a reason, to protect you. There's no point in turning down your protection you have built in to your computer.
To back up this point I found a post from Sophos, a security software company that found a random sample of 10 malware samples 7 infected Windows 7 running UAC at its default mode. It also ran the test on a machine running no security software. http://www.sophos.com/blogs/chetw/g/2009/11/03/windows-7-vulnerable
Neowin a popular Windows blog however cried fowl, and ripped the methodology of the "study" and I admit Sophos sells sell security software so their motives might be questionable. But I still think it's prudent and wise to turn up your UAC. http://www.neowin.net/news/main/09/11/04/sophos-windows-7-vulnerable-to-810-viruses-fud-alert
So the next step after turning up UAC is to make sure you have an antivirus program. The free Microsoft Security Essentials is a fine, free program and I'm running it on several machines. I'd also get Malwarebytes anti Malware software and top it off with Superantispyware another great antispyware program. Another common item on the security checklist is to type "Folders" into the start search, open "Folder Options" and select "View". Uncheck "Hide Extensions for known File Types" this way when someone sends you a picture you normally see as a .jpg file you will see the jpg.exe it really is. Pictures don't normally have executables in them, and for some unknown reason Microsoft continues to hide known extensions by default.
Security threats being what they are, a few quick techniques will help keep you safe, even with the latest and greatest from Microsoft.