Along with MBAM, it might be a good idea to run SuperAntiSpyware as well. Both should be updated (Manually if necessary) and then run in Safe Mode.
If these fail to find anything but malware is still suspected, download and burn (On a clean machine) the Kaspersky Rescue 10
ISO. This is a very useful tool to have anyway and I'd recommend that everyone grabs a copy.
Reboot and check the router settings and cables etc.
Ensure that the machine is connected to the LAN and has internet access available to it. The KRD will see and successfully configure many WLAN devices but success with this isn't guaranteed.
When the CD is created, boot the bad box from it and choose the Graphical Interface, accept the EULA, set the desired connection options from the network configurator daemon and then update the databases.
Set your desired scan options and let it go. Clean anything that it finds and before rebooting, see if you can browse the local network via the CD. There's a basic file manager included.
If malware isn't a suspect, check the Event Logs. If connection is an issue, check that the correct IP, gateway etc info is present and ping the router and then Google or whatever. If pinging the internet is successful, check the defaut browser's settings, run it and see what happens. If IE, Use the No Addons version first.
Check that "Simple File Sharing" is enabled and that all necessary services etc are present and running and access perms etc are good.
If that's OK, check that the workgroup/machine names are common/unique to each box.
Check software firewalls/other security software isn't blocking things.
If pinging the "good" machine is succesful, create a shared folder on it and try to navigate to it from the afflicted box.
If successful, ensure that the good boxes printers are shared and that the bad box can now see and use them.
Edited by Deadbeat (Wed 06-Apr-11 04:05:52)