回复：有人知道怎么清除adstartup吗

Use Google to download "HijackThis".
Run it on your computer and use it to fix these two:

BHO: (no name) - {0B90AA1B-F649-44C3-9FD3-736C332CBBCF} - C:\WINNT\System32\IEENHA~1.DLL

HKLM\..\Run: [Adstartup] C:\WINNT\System32\Adstartup.exe

May not exactly same but sth like above.