David installed what appeared to be one ordinary program, but the installer brought along approximately half a dozen additional programs. After he rebooted the computer, Windows was no longer behaving normally.

The infection had gone beyond annoying advertisements or browser pop-ups. Task Manager would not open, and attempts to use Command Prompt produced error 0xc0000142. That error means a program could not initialize one of the Windows components it depended on. In the context of a heavily infected computer, it pointed to system files or DLL components that had been damaged, replaced, or interfered with by the unwanted software.

This made the cleanup more difficult because the normal Windows tools used to investigate a problem were also failing. The unwanted programs had to be removed carefully while the damaged Windows components were repaired and the system was checked for anything left behind.

After the malware cleanup and Windows repair were completed, the computer returned to normal operation. David’s experience is a good example of why even a single download can become a serious Windows problem when an installer quietly bundles several other programs with it.

At that point, simply uninstalling the visible unwanted programs would not have been enough. Because Windows’ own management and command-line tools were affected, the repair also had to restore the damaged operating-system components and confirm that the computer remained stable after the unwanted software was removed.

Related service: Virus, Malware & Browser Cleanup.