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Simply disable your antivirus in this instance to check for sure if they are the reason why you can't open the attachments or not. Attachments are part of such incoming data and so in the course of doing their work, the antivirus programs may stop you from having access to your attachments. How does this work? Antivirus programs work to secure your system from all incoming data to your PC. Some antivirus programs you have installed on your system may be the reason you cannot open your attachments in Outlook.
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If you want to use this particular program to open all your attachments going forward, tick the box beside the option "Always use this app to open" and select "OK".exe (executable) file of the program on your PC and choose "OK" to make the program your default attachment opening program Can't find your preferred program? Do not worry, just tap the "Browse" option, locate the.Click on the program you wish to use for opening your file and tap "Apply" or "OK".
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Here, choose "Change" to see different programs from which you can choose.
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The first major reason why you may not be able to open an attachment in outlook is that the file is in a format that your computer cannot recognize.
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