@ mflynn First of all, many thanks for continuing to show interest and provide advice, I hope I’m not a bad pupil. As I said before, I have increased my personal knowledge, anti-malware arsenal and system security as a result of this thread. Another reply to a question of yours: I clarify that SiSoftware is indeed installed, but in the Startup list (Start> Run> services.msc) is shown as starting manually, not automatically with Windows. Is it shown by HJT as being activated, i.e. starting automatically? As regards malware still detected by various tools, I had noticed in the past that each tool tends to find items quarantined by another and signal a new discovery, when in fact it’s an already known and fixed issue. I just hope this is not happening in my case. It’s also possible that de-activating all real-time protection during scans leaves the way open for new invaders. How likely do you consider this when there is internet connection but no browser open? I shall now proceed with the other measures you mentioned. I have been busy doing further scans with AntiVir & Ad-Aware.