Disable movie/video thumbnail preview under Windows XP

Rather annoyingly, the explorer.exe process under Windows XP can sometimes hang, stop responding, crash or just plain terminate/close itself while it tries to display video/movie thumbnails in any given folder.

The reason for this can be a multitude of issues – like a dodgy codec, etc – and seems to be rather in-discriminant as to which file type it decides to screw up with (AVI, MPG, WMV, ASF, etc).

To get around this problem though, it is possible to easily disable this feature. Either fire up a command prompt or execute this straight from the run dialog box:

regsvr32 /u shmedia.dll

And if you want to re-enable it again at a later date:

regsvr32 shmedia.dll

Now, the only knock-on effect is that you’ll no longer be able to see summary information in the file properties. In my opinion though, it’s a small price to pay!!

Terminate current VPN sessions on Cisco router/ASA

Many a time I have to kick remote users off a Cisco router / ASA box. This depends on your configuration – but here’s how to close one or all VPN user sessions on the PPTP setup we created in an earlier how-to. First, we’ll check to see who’s online:

phbrtr#sh vpdn session

PPTP Session Information Total tunnels 1 sessions 1

LocID RemID TunID Intf   Username State    Last Chg    Uniq ID
32       32768   37       Vi3   user            estabd 00:00:18   31
phbrtr#

That pesky user!! Lets disconnect him..

phbrtr#clear vpdn tunnel pptp id 37
Starting to clear the tunnel
phbrtr#

Note here that we’ve used the TunID from the previous command (in this case – 37). Another quick ’show vpdn session’ (or for the lazy: ’sh u’) will show that your user has disappeared.

If you’ve got a lot of users, looking up their id and clearing can be quite tedious. To clear ALL PPTP sessions:

phbrtr#clear vpdn tunnel pptp all
Clear all PPTP tunnels? [confirm]
Starting to clear the tunnel

phbrtr#

Simples!