How to prevent Notepad++ search to loop

To answer the question there is not that functionality, but it would be a good idea. Feature requests for Notepad++ can be submitted through IdeaTorrent.

A work around is to use a regular expression that swallows the rest of the line. For example is you want to find lines containing abc you can search for '.*abc.*' under regular expressions and that will find every line with abc but will only list it once.

Some times, programs can start via a scheduled task. So, check there for anything you're not sure of.

Also, and I can't think of why any program would do this for Notepad++, but it could be possible that another program is opening NotePad ++ (eg, a malicious script loads it up for no good reason).

Lastly, it is possible that an update has occurred on the software itself. So, yes, you are right to check the MSCONFIG but also look through the NotePad ++ settings and ensure that it is not set to load with Windows.

If none of the above help, then it is possible that the default programs are set incorrectly. For example (and this is a silly example but it does demonstrate the theory), let's assume my PC was set to open a web page every time Windows loaded but for a strange reason I bug made all web pages to open with NotePad++ (which I was unaware of), this could then occur. Although it's not typical, this has happened to me once before at work.