Whooa!!! Slow down.
First: what was the error???
Second: download and install a (free) utility called CCleaner (link below) and run it (ensure that ALL the options are 'ticked'). This will remove the currently invalid entry from your registry which will allow you to re-install the software. I've used this utility for years now (on my and my clients workstations) and I assure you it's virus and spyware free.
CCleaner - Home
By the way: more and more often I'm finding that my clients are having trouble when installing the latest version of Delta Trading and then my indicators. The problem that keeps recurring is the fact that they either get errors on the charts OR cannot see the charts at all. The fix for this is to ENSURE that you have used Microsoft Windows Update to update your Windows Operating System. Do not use the 'Express' update option but rather use the 'Custom' update option and then select 'Recommended Updates' and MAKE SURE that ALL updates that relate to the Microsoft Windows .NET Framework (for ALL VERSIONS) are selected and installed. DON'T bother downloading the Microsoft .NET Framework installation software from Delta's website i.e. it does NOT fix the problem.