Hello, I'm having the same problem. Whenever I try to search something from the start menu, explorer's CPU usage goes near 100% and stays there for a while (probably searching through the hard drive).
When I found this thread, I checked my Windows Search settings. Windows Search is enabled and is indexing a small bunch of folders. I thought it was probably continuing its search in non-indexed locations, so I added the whole C drive (no other drives in use) to the index and waited till indexing service was finished indexing it. Still had the same problem. Then I noticed that Windows still excluded a bunch of system directories from the indexer. After I added those too, it seemed to work faster and not cause explorer to hog CPU anymore. However, it makes no sense to have to index every single directory on the file system.
Windows 7 seems to only search from indexed locations when using the start menu. It would make sense if Start8 did the same, since indexing the whole drive seems pointless and wastes resources. And perhaps if Windows Search Service was completely disabled, it could search from some specific predetermined locations, such as Start Menu folder and/or wherever Windows 8 stores its application shortcuts.
A few things I've noticed so far:
* The icons used in "Recent" lists are only shown if the file still exists. Perhaps there could be some default icon to fill the empty space or the default icon for that file extension could be used then.
* When I open Start8 settings, "Default Theme" is always the selected theme, no matter which theme was actually in use when I launched Start8 settings.
One last question, are Control Panel sections going to be searchable in the next versions?
Generally it seems to be a great product - plenty of customization options. Makes the "touch-OS" usable on a PC. Currently I'm using the trial version, probably going to buy it.