TOPIC: installation of new version

I just downloaded the 2.7.5 version, and tried to install it on my website on which I already have the 2.7.4c version installed.

In the Extension manager I get an error ''Another Component is already using directory: ..."

How can this be resolved?

There is a README file in the zip folder which contains directions for upgrading. Here is a copy from the 2.7.5 install (there are other things in the readme file as well so you may want to actually look at that instead of just this list):

/// UPGRADING FROM DT REGISTER 2.7.0 or later ///

1. Backup your files and database just in case you experience any problems during or after the upgrade.
2. Download a copy of any CSS files, modified images, and the two language files IF you have made any changes to any of these files. If you haven't made changes, skip this step.
3. Uninstall the current version of DT Register. Your records, events, configuration, etc will NOT be removed. Files are
replaced but all data is left alone.
4. Install the new version of DT Register for Joomla 1.5.x.
5. IF you have changes in any CSS file or images, you can reload them to your new installation as there are no changes to these items at this time.
6. IF you have changes in your language files, DO NOT reload them to your new installation. There will be new language items that you will need. You will find two language files for DT Register... one for the frontend and one for the backend (administrator area).
These files are located at:
/language/en-GB/en-GB.com_dtregister.ini
/administrator/language/en-GB/en-GB.com_dtregister.ini
If you have previously made any changes to your DT Register language files, you will need to re-apply them to these new files or just add the new language items which will be found at the bottom of the new language files.
7. After completing the upgrade, you need to go to the DT Register Configuration, set all new parameters and SAVE. You should be all set now!