windows aero disabled

message found when I started my computer:

"Failed to connect to a windows service.
Windows could not connect to the System Event Notification Service service. This problem prevents limited users from logging on to the system. As an administrative user, you can review the System Event Log for details about why the service didn't respond."

Last night I have recently updated my windows defender and my nvidia GeForce 7100 GS since my windows 7 prompted me to do so.

my rate is 3.0

This morning I have turned on my computer and was given the message above.

Symptoms:
1. windows aero disabled
2. Desktop Window Manager enabled but the themes said it was disabled.
3. my sound card doesn't work

Resolutions:
1. diagnostics troubleshoot wizard
2. Need help with windows 7 aero
3. How to turn on Windows 7 Aero theme | Web Talk
4. the bios solution (lost the link)
5. scanning my computer for malware

Please help me.

P.S. attached is a screenshot for troubleshooting.

doing SFC scan as we speak. it just need a few more minutes


====================================================
*scan done.

windows resource protection did not find any integrity violations.

Restore your system back to the previous point of upgrading nvidia .