I have closed every window, restarted the computer. But Eclipse is telling me: \"C:\\Program Files\\android-sdk\\tools is being accessed....I even deleted the directory but
I have had this problem on Windows too. Instead of updating it through Eclipse, try the stand-alone option:
If you have the SDK tools directory in your path it will open the same UI you get in Eclipse but without additional file locking. If it is not in your path have a look in C:\Program Files\Android\android-sdk\tools
and run "android.bat" from there.
Also, once you have updated the SDK, don't forget to fire up Eclipse and, on the Help menu, click "Check for Updates". You may well find the ADK Eclipse plugin needs to be updated too - this often goes in step with SDK updates.