I think most people have it activated. Be aware it does take some resourses when running in the back ground.
Here is a good description of TeaTimer:
ResidentTeaTimer Tools
What is the Resident TeaTimer?
The Resident TeaTimer is a new tool of Spybot-S&D which perpetually monitors the processes called/initiated. It immediately detects known malicious processes wanting to start and terminates them giving you some options how to deal with this process in the future: You can set TeaTimer to:
- be informed, when the process tries to start again
- automatically kill the process
- or generally allow the process to run There is also an option to delete the file associated with this process.
In addition, TeaTimer detects, when something wants to change some critical registry keys. TeaTimer can protect you against such changes again giving you an option: You can either "Allow" or "Deny" the change. As TeaTimer is always running in the background, it takes some resources of about 5 MB.