A clean, tabbed layout makes Registry Booster easy to use, and its Registry-centric features keep it focused and in fighting trim. The trial version comes burdened by some tight restrictions that will make it hard for average users to evaluate, but the program does a surprisingly good job of showing you precisely what would be fixed.
Annoyingly, after the program installs, if you choose to launch it immediately it will go directly into a scan without asking for user approval. Depending on your system resources and what other programs you have open, this could lead to a temporary but dramatic system slowdown. Once that first scan is complete, Registry Booster will take you directly to the Registry Scan tab and the scan results suboption. From there, click the small View Results link at the bottom of the pane to see a log of which Registry keys were flagged as problematic. The log will show you the key locations, too. Other left-nav tabs allow you to set an Ignore list, view saved cleaning logs, and defrag your Registry. You can also toggle Minimize and Close button behavior, as well as setting the program to run at Windows start-up or run a scan when it launches.
The trialware allows for only 15 sections of the Registry to be repaired, and the Registry defragger is similarly truncated. Running the program did clear up 15 problems in the Registry, although it would be better if users could determine which 15 problems get fixed so that we could better gauge Registry Booster's efficacy. A less noticeable problem was that the program incorrectly showed the amount of physical memory on the test computer under the System Information tab, calculating 2GB of RAM when there was actually 3GB. Registry Booster is a decent and focused Registry tool, but a more open trial might convince more people that the program is worth buying.