Funny mine are working fine. I have two weather gadgets and a date gadget with a CPU gadget all from the MS site. They have not caused any problems nor have I ever turned them off.
With Vista they don't use much noticeable CPU at all. The weather gadgets both need to be open to the internet to function but they don't cause any strain to any program I have including Sonar.
Although I think Freddie is right in his warning if people use some common sense when they add stuff to their computer and use MS Security Essentials, they should be well protected.
I have not been bothered by any virus or malicious program since going Vista. But then I didn't have any problem with XP either. Vista/Win 7 are very robust OSs when it comes to security if you use your head and not undermine it by disregarding warnings and sensible procedures.
64 bit computing is also helpful in this regard.
There are plenty of don'ts one should follow but you all know what those are.
Don't go to sites that are suspect. Don't download stuff that is of dubious origin.
Be sure you don't open email that you don't know anything about.
And don't click on links at all when you can't be sure where it will take you.
Use a browser that is secure.
One can go on and on but use your common sense and you will be fine.
One last thing if someone really wants to get into your computer there is very little you can do to stop them. In my case they would be bored out of their skulls.