Many and remember I can't guess or list them all such as Norton, Kapersky and others block your internet connection when expired or when the date/time is too far off.
The only good news here is that you know it deleted the files needed to use your (unknown) 4g modem so you can remove the antivirus and reinstall your 4g software.
Please help, my antivirus has turned against me and deleted my 4g modem connection software exes, so I can't access the internet and to top it all of, my modem itself isn't showing up in my computer, so the only way I can access internet is if I enter safe mode, repair the file throu the modem, since in safe mode the pc finds it and then uninstall the antivirus so that it can't delete the shortcut and exe on startup. I've scanned throu my system with avast antyvirus, windows defender, tuneup utilities and combofix and they all found nothing. Is there anything I can do or must I resort to reinstalling windows? Ohh and don't think that the antivirus itself is **** or that my modem is ****, because ive been using them both for over 3 years