Hello Raul Miguel & welcome to the Avast Forums,
I have pasted the translation of your post below for everyone's reference. Are you experiencing some problems or is there some specific type of help you need? If so, please be so kind as to provide some details to enable other forum members to better assist you.
----------------TRANSLATION OF THE OP'S POST------------------
The presentation can not be opened. Your antivirus program may be preventing this action. To correct the problem, make sure your antivirus program is up and running properly. If the problem persists and the presentation is from a trusted source, disable your antivirus program and try to open the presentation again. In this case, do not forget to reenable your antivirus program after opening the presentation.
Best regards,