The Ultimate Troubleshooter ($30; free, ten-use, feature-limited demo), as its name implies, promises to troubleshoot any and all problems you may run across when running your PC. However, it's not nearly as useful or powerful as similar programs, and the trial version is so lacking in basic features that you'll most likely want to stay away.
The Ultimate Troubleshooter (TUT for short) offers information about current tasks and services running on your PC, what programs run on startup, and system information. But it doesn't go beyond that, and doesn't really offer troubleshooting tools. There's no Registry cleaner, for example. And the Windows tuning feature is very rudimentary, and only offers relatively simple advice.
Making matters worse, the demo version of TUT (good for only 10 uses), is partially crippled. When it finds tasks that it believes may not be good for your system, it won't give you information about all of them, unless you buy the full program.