Deleting a service:

sc delete servicename

http://www.tweakxp.com/tweak1976.aspx
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Startup Registry:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\policies\Explorer\Run 
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce 

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Untested, but seems to work in command prompt:

The /dev/null equivalent for windows is NUL

http://www.acmeconsulting.it/pagine/opensource/squid/Cygwin-svc/

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Reboot the machine

SHUTDOWN -r -t 01

Or via remote desktop, use the task manager.