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Hi! Pls help, which free app to use to convert .exe file to something compatible with my iPad?
Unfortunately you're unlikely to ever find such a program, free or otherwise.
.exe files are generally designed for the Microsoft Windows operating system and PC's.
iOS apps are designed for your Apple iPad your tablet computer, iPod Touch, and iPhone.
If it's for work, and they gave you the iPad, ask them where to locate the appropriate iOS apps you need.
Without going into all the details, it's unlikely that there will ever be that kind of software available for iOS, because of the huge differences between PC and tablet hardware architecture, software, and file systems.
There ARE iOS apps that can open, view, and perhaps edit some common document formats created by Windows PC's, such as .doc or .docx files from Microsoft Word, and .xls or .xlsx spreadsheets created by Microsoft Excel. I don't use any of them (because I have a Mac and a PC for such things), so I won't recommend any.