check any software installed on client computer

[question]

is it possible to check whether a software(skype) is installed on the client machine or not? for example, i can check it in my computer under regedit the installation path (C:\Program Files\Skype...)
and i can check it with FileExists, but i dont know whether the client installed it on C or D or any other drive,then how can i check it ?

[Luckie]

I don't really get what your problem or your intention is.

If the software is install via an installer there should be an installer entry in the registry. (Use Google to find the appropriate registry key.) But this only works for software with an uninstallers.

[Furtbichler]

Zitat von question:

is it possible to check whether a software(skype) is installed on the client machine

Zitat von Luckie:

I don't really get what your problem or your intention is.

To be honest, it is very clear in my eyes.
However, besides Luckie's answer (which would cover most apps) you would have to search individually for each software. Most of the application will use the registry somehow so you could check for a specific entry. But you'd have to know which one to look for.

[question]

Thank you for your information, actually i my question was, if i click the button then it will it show me the result
"skype has already installed on this machine" // if skype is installed
otherwise
it will show me the message
"skype is not installed yet"

[DeddyH]

Something like this

Delphi-Quellcode:

function SkypeInstalled: Boolean;
begin
  (* Code *)
end;

procedure TSomeForm.SomeButtonClick(Sender: TObject);
begin
  if SkypeInstalled then
    ShowMessage('Skype is already installed')
  else
    ShowMessage('Skype has not been installed yet');
end;