TOPIC: Install errors 2.7.1

I was installing DT Register 2.7.1 on a new site (Joomla 1.5.22) as a test site on my laptop.
The laptop got "busy" doing an unexpected background job during the installation of DT Register and a message appeared with a "timeout".

Then it appeared that another component was using the folder for DT Register but I was not able to "uninstall DTRegister" as it did not show up in the list of components.

Any suggestions?