adding reference information

hi i am new in using Endnote. i had many files in my laptop . i imported them to the library but the documents’ information is not inserted correctly . how to get the correct data of the references . should i insert them manually one by one ? or is there away to retrive it

Using Endnote20 or a previous version. Is there any info imported correctly?  I am not sure the update record function is working on Endnote20.