PowerPoint Uploading Error

[SusanAtGuidedMeetings]

The group of folks I am working with are mostly using windows-based PC's.  When they attempt to upload a PowerPoint they always get an error message during the converting stage and when attempting to upload the PPTs to the Content Library.  I and another person - who are using Macs - can both upload these same PowerPoints in the meeting room and to the Content Library with no problem.  I spoke with an AC rep at a conference and he felt that this is probably an issue with some settings on the PC-users computers...but didn't have any suggestions as to what the settings are.  The PC's are running Windows (probably 7 and 8, most likely 7) and Office 2010.  What should I be looking for in their system, as well as on the computers, that could be causing this error consistently?  TIA!

[Jorma_at_CoSo]

Have them try uploading a version of the deck as a PPT instead of a PPTX.

[SusanAtGuidedMeetings]

Thanks, Jorma...I have done that...as well as have them reduce file size.

[AAnkurA]

Please check if any PowerPoint modal dialog is opened while uploading PPTX files in meeting. If any modal dialog like "Save As" dialog is opened while uploading in meeting then it will result in an error.

[SusanAtGuidedMeetings]

Thank you GHick!  I will explore that!