Howtogeek posted a guide about making the Windows 7 Start Menu search faster

When you first get your shiny new Windows 7 PC, typing anything into the Start Menu search box returns exactly what you want instantly? but what about once you've built up loads of files? It tends to get really slow, but here's how to fix it.
Note: we're assuming that you already use Disk Cleanup on a regular basis, or maybe you've already setup CCleaner to clean your PC on a schedule. Still slow? Keep reading.

  Make Windows 7 Start Menu Search Find Your Applications Faster