I would not run Advanced System care as it causes problems, as do all optimizers and tweaking tools except CCleaner.
AVG is also not recommended by anyone here. Use
Microsoft Security Essentials with the Windows 7 Firewall, keep Windows Updates set to Automatic to get all security, performance and
driver updates.
Use on-demand
Malwarebytes scanner, upgrade to real-time protection if you get infected much.
For now work through these steps for
Troubleshooting Windows 7 Failure to Start