Answers:
ya your system may be affect by Virus those that virus is trying to communication trough your internet during that ubnormal condition the connect will take broke and system restart itself because of firewall
Scan your system fully using update Antivrus .
your can prevent restarting where on earth as its be done by Firewall
goto exchange cards properties - > find firewall setting here you can find some way out approaching restart my computer when suspicious program trying to connect internet ( not exact ) remove that chance .
subsequent time when you connect to Net its show admonition solely it wonot restart .
check this relation it may help you
format the c drive an re install all the software, may solve u r prob an virus attact may be the principle
virus in system 32 .
re install Windows by repair command
when you use Internet it is essential that an live updated antivirals to protect your computer
turn free software>antivirals > down nouns >install
Go to event bystander within control panel/administrative tools and see the reports generate and find the exact probelm first. We after can own the best solution. Formating the system is the final step. First to do the troubleshooting of the complaint.
All the best