computer locking up when running browsers

hello,

i have a alienware x51 64 based pc running windows 7 home premium. i have had an issue for a few weeks and am posting a question in hopes to get some help.

in event viewer at the time of freeze i get following errors. not sure which one could cause a system lockup:

event 11, winit
Custom dynamic link libraries are being loaded for every application. The system administrator should review the list of libraries to ensure they are related to trusted applications.

event 1, rtl8167
Realtek PCIe GBE Family Controller is disconnected from network.

event 7001, service control manager
The Computer Browser service depends on the Server service which failed to start because of the following error: The dependency service or group failed to start.

event 10005, distributredcom
DCOM got error "1084" attempting to start the service ShellHWDetection with arguments "" in order to run the server: {DD522ACC-F821-461A-A407-50B198B896DC}

event  nvlddmkm
The description for Event ID 14 from source nvlddmkm cannot be found. Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer.

If the event originated on another computer, the display information had to be saved with the event.

The following information was included with the event:

\Device\Video5
CMDre 00000006 00000000 ffffffff 00000000 00000000

thanks so much,

marybeth