Unexpected shutdowns

Hi,
Michael Tsirlin here.
User troteris

Recently I noticed that my computer makes strange shutdowns.
When I out of computer for a long time and return I find message
"Windows has recovered from unexpected shutdown"
It occurs just when I absent from my computer for one hour or more.


Yesterday I found the way to see reasons for these shutdowns.
Event viewer gives me errors that shutdown computer.
Yesterday it was Flash player today more serious

Service Control manager

Level Date and Time Source Event ID Task Category
Error 30/05/2011 10:33:57 AM Service Control Manager 7000 None
"The Security Services Driver (x64) service failed to start due to the following error:
The system cannot find the file specified."
Service Control manager

Level Date and Time Source Event ID Task Category
Error 30/05/2011 10:33:56 AM Service Control Manager 7001 None
"The NVIDIA Display Driver Service service depends on the nvlddmkm service
which failed to start because of the following error:
The service cannot be started, either because it is disabled or because it has no enabled devices associated with it."


WMI

Level Date and Time Source Event ID Task Category
Error 30/05/2011 10:33:56 AM Microsoft-Windows-WMI 10 None
"Event filter with query ""SELECT * FROM __InstanceModificationEvent WITHIN 60 WHERE
TargetInstance ISA ""Win32_Processor"" AND TargetInstance.LoadPercentage >
99"" could not be reactivated in namespace ""//./root/CIMV2"" because of error
0x80041003. Events cannot be delivered through this filter until the problem is corrected."


What’s going on and how to deal with it?


Thanks

Michael Tsirlin