If anyone might be able to provide some assistance, I would be grateful. I have contracted the Backdoor.Optix trojan and I cannot get rid of it. I use Norton AntiVirus and it located the file causing the problem but I cannot delete it. It seems that when my computer boots, a command file (windows.com) is loaded from C:\Windows\System32 and begins a process that runs in the backgroud. So long as the process is running, I cannot delete the file. But when I end the process via the Windows Task Manager, the windows.com file disappears. I cannot remove the Norton warning and multiple scans have failed to properly remove the trojan.
There is also an executable (yahooupdate.exe) that is related but also disappears when I click on it.