Flood and Flood's wife, thanks for your helpful assistance and feedback. I will follow up on your responses in order. The file SppExtComObjHook.dll does exist at C:\Windows\System32\SppExtComObjHook.dll, but is not shown up when trying to select from Exclusions in Kaspersky. Please refer to attached screenshots below. I will use the *.* mask you advised for C:\Program Files (x86)\Adobe\Adobe 11.0\Acrobat\, as shown in your screenshot. I am extremely confused about this. You are saying that the Kaspersky application from www.kaspersky.com.au/free-antivirus is Kaspersky Free for Windows, from Kaspersky's *new* MR5 range; it replaces Kaspersky Security Cloud Free. Note that, as shown in the attached screenshot, the version of the Kaspersky Free for Windows that I installed is 21.5.11.384 (b). Now, if you go to support.kaspersky.com/kfa this says: Switch to new Kaspersky Security Cloud Free In the nearest future we are going to replace Kaspersky Free with a more advanced solution — Kaspersky Security Cloud Free. In some time we will gradually start discontinuing the support of Kaspersky Free: we will stop releasing antivirus database updates, therefore protection against latest threats will no longer be guaranteed. Kaspersky Security Cloud Free is already available and we encourage you to switch to it as soon as possible. So, all of this is contradictory: on one hand you are saying that Kaspersky Free for Windows, from Kaspersky's *new* MR5 range (what is MR5 range?), it replaces Kaspersky Security Cloud Free, and on the other hand Kaspersky is clearly saying that Kaspersky Free will be replaced by Kaspersky Security Cloud Free, encouraging users to switch to it as soon as possible. Also what is MR5 (and MR4, MR3, etc.), what does it stand for? Also, where can I find the version history for each Kaspersky application? harlan4096, thanks for your insightful feedback. Luckily I can read Spanish, so I will read carefully the link that you provided. This file SppExtComObjHook.dll is definitely not a malicious program (I have carefully checked that) but a program that allows resetting again the countdown period for a Microsoft Office demo suite that I have. So I want to keep this file and not have it deleted/removed. harlan4096, what is not clear, in order to select specifically the SppExtComObjHook.dll file in the way describe in the Spanish link that you provided (https://community.kaspersky.com/para%2Dusuarios%2Dparticulares%2Dforum%2Dpara%2Dusuarios%2Dhispanohablantes%2D70/exclusiones%2Dignoradas%2D21828?postid=94109#post94109), you need to specify the Object name. My question is: how do I identify the Object name for my SppExtComObjHook.dll file ? Thank you very much for your help.