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
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