Why is teatimer constantly running registry operations?

"TeaTimer is the part of SpyBot that supposed to pro-actively protects your system from infection and/or spot the infection immediately rather than waiting for you to manually run a full Spybot scan.

As one of the things Teatimer does is watch your registry for suspicious changes you'll probably find that every time another app makes a registry change Teatimer jumps in straight afterwards and checks that this isn't a harmful change. This means that Teatimer is bound to be the top registry accesser as its job is to do nearly as many accesses as all your other apps put together.

Any continuously running spyware/anti-virus/firewall app is going to be a drain on system resources as they're always double-checking what your other apps are up to, whether or not you're happy with the trade-off between system speed and system security is totally your judgement call.

Teatimer is only an optional part of the Spybot install, you don't have to install it if you don't want to."

"Is this a drain on system resources?

it sure is, big time.

run your web browser (and other web-related applications) in an isolated environment (i.e. Sandboxie) where they belong and be done with superfluous gimmicks such as 'Teatimer'."