Adobe Reader DC FIPS 140-2 Mode Inquiry

We use Adobe Reader DC on Windows 10 in our work environment, and wanted to know if there are any alternative solution for opening and digitally signing older PDF format files that have have non-compliment signatures or algorithms already applied without turning off FIPS 140-2 mode, is there a PDF conversion tool built in or can be can downloaded from Adobe to assist in converting these files to the appropriate format so they are still able to be opened and utilized with Adobe Reader DC, and without having to use Adobe Acrobat Pro.