virtualbox.org

I once installed VB on my pc running windows xp professional fully updated. Ran VB with Linux/Other to try out Joomla. Followed the tutorial on joomla.org http://demo.joomla.org/jumpbox.html. Now suddenly when I had rebooted after removing the linux/other vb and uninstalled joomla I couldn't get online anymore. My wifi card and lan port was and is still listed as hardware with the appropriate drivers. I tried uninstalling VB but got a "Fatal error during isntallation" during the uninstall process, and ever since the there haven't been any "uninstall" option in the VB folder (though start -> programs) or in add/remove programs. I am still able to start VB like nothing ever happened. At this time the computer also refuses to shut down properly 90 % of the time. It gives the message "Shutting down" then the box containing the message disappears and I'm left with a black screen and a mouse still functioning at which point I have to force shut down.

I have also tried removing the Virtual Box Host Only Ethernet Adapter from hardware manager, but it ends up freezing and I have to enter job manager to kill the device manager which at last gives me the information that mmc.exe doesn't respond.

Any idears? : )
Sorry for the block of text I am writing this in the late hours.

Try the VBox install itself. It should let you install, uninstall, or repair.
If it sees that it is there you can repair or uninstall.
If it does not see it then you will need to install and then uninstall if the install does not fix your problem.
Then you can install and everything should be back to normal.

I have tried that and VB wants to rollback before it can install properly. The rollback action stops at around 95 % and hangs there forever. Do you have any other idears? I can't figure out why it won't work.

Did you have a previous version of VBox that was older than 3.0.0 and try to upgrade?
Here are a few things to try:

http://www.virtualbox.org/ticket/3701

Or (jump to 2a) since you have already tried that.

1. Right click on the install program and then left click on run as admin.
or
2a If that fails you need to reinstall version 2.2.0 and select repair. (DO NOT reboot)
2b Run the version 2.2.0 install again and tell it to uninstall (DO NOT reboot)
2c Run the new Version 3.0.2 install and see if it works (This time reboot)