I've used Windows Live-OneCare and didn't think highly of it at all. It's a waste of system resources and space in my opinion. My impression was that the majority of tasks OneCare performs are already tools included with your Windows operating system from Microsoft.
The advice below will offer you a better/broader range of internet security, as well as equal maintenance operations as compared to OneCare:
1. Download both free versions of anti virus/internet security programs, AVG by Grisoft, and Windows Defender by Microsoft.
2. Perform daily updates, scans and event logs with both programs.
3. Use your 'Control Panel' to practice regular performance & maintenance tasks such as, disc clean-up, disc defragmenter and configuring automatic updates.
4. Switch your default web browser from Internet Explorer to a more secure web browser like Mozilla Firefox.
5. Use the 'Tools' tab in your web browser to elevate your security settings. Occasionally clear your private data- saved passwords, cookies, temp internet files, etc...
6. Use the 'Task Manager' to end unimportant programs/processes taking up system resources. Google the descriptions/details of each process before ending it, in order to avoid causing system instability or failure.
7. Type msconfig in the 'Run' window, located under your Start menu. You can disable unimportant programs/services from running upon system startup. Again, use caution and Google the importance of any program in question.
Keep in mind that these methods merely scratch the surface as far as computer security and performance are concerned, but hopefully you'll find this information useful . However, on the chance that none of this stuff is new news to you, then at least you'll realize OneCare is pointless!