If other computers are running fine then the router is unlikely to be the issue. Since you mentioned that windows had run some updates then please answer these questions.
Which security software are you running?
Check Control Panel -> Add/Remove programs. Make sure that Show Updates is checked. Look through the list and check for a windows update that has KB951748 listed in there. Is it there?
If you are running Zone Alarm (any product) and have this update installed then do one of the following.
Disable ZoneAlarm
Reduce security to Medium in ZoneAlarm
Remove the security update.
Once that is done then update ZoneAlarm to resolve the issue.
Source: http://download.zonealarm.com/bin/fr...cessIssue.html
Note that some machines have other security software and it still breaks so remove the update anyways and see if it resolves it. If it does then get with your security software vendor and see if there was an update released to resolve the conflict.