problem in Installing android sdk platform

i am getting the following error when i download android sdk version lower than 2.3 and

Downloading SDK Platform Android 2.2, API 8, revision 2 Installing SDK Platform Android 2.2, API 8, revision 2 Unzip failed: C:\Program Files\Android\android-sdk\platforms\android-8\tools\dexdump.exe (Access is denied)

when i created a project in eclipse its showing following error Dex Loader] Unable to execute dex: wrapper was not properly loaded first [2011-07-16 12:14:08 - hell] Conver开发者_如何学Csion to Dalvik format failed: Unable to execute dex: wrapper was not properly loaded first.please help i dont know why i am getting this problem.

Make sure you have the proper permissions to load the file. This would be a problem if you're using a work or school computer that has the SDK installed by an administrator. Then, try rebooting if some program got hung and locked the file. If neither of those things work, I would try installing the SDK again to a different directory. It's a bit drastic, but if it's the only option you have left, it's almost guaranteed to work.