The problem has been resolved for me by trawling for other people having COM issues. Try giving full control permissions for “Administrators” using the RegEDIT tool to change permissions on the folder key “HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesEventlogSecurity”. Vegas Pro 8 and the demo of Vegas Pro 9 were both aided by this fix. I’d previously given up on installing this for when I’m using my wife’s PC but my ambition to demo VP9 encouraged me to try harder!
Right mouse this folder in regedit. Confirm Administrators is ticked for FULL CONTROL, if it isn’t – this might fix all your troubles!
Not sure how Windows gets into a state where you can’t control this resource even while you are logged in as an Administrator. Also, YMMV – and only go into regedit if you feel competent that you could change ANYTHING you alter back by yourself please.