To prevent this automatic downloading and prompt, do the followings:
- Find your temp folder, for Windows 7, it is: C:\Users\UserName\AppData\Local\Temp. If you cannot see this folder, you need to enable showing hidden system folders and files.
- Download the fake "SkyepSetup.exe" file from here and put it into above temp folder.
- Right click on this file, Properties, Security, Edit, deny all access for all users.
BTW, you should always use the portable versions for Skype and QQ (2011) .