Are the any computer malware or spyware that need a system reboot so that they can function properly?

Are there any malware, or spyware that needs a forced system reboot to work correctly? Because whenever a major security update or release for Windows comes out, or if I zero out my disks and install a totally fresh copy of Windows, there is always a power cut where I live. To me, it seems something on my system needs a reboot. Is this all my imagination or could there be something going on?