I tried to update my Eclipse IDE to Android 2.3. After update completes, adb.exe file goes missing. It corrupted my development setup. I was unable to update after "adb.exe not fount error". Finally, removed all updates & installed them again. That worked!
Updating from Android 2.2 to Android 2.3 does not work for all due to some issue with update manager. "adb.exe" not found error comes cause android 2.3 onwards "adb.exe" file is moved from tools folder to platform-tools folder.