The 2.60 is indeed the latest bios for your model. Asrock points that its best if you are using win 10 to update the bios via instant flash.
"Instant Flash is a UEFI flash utility embedded in Flash ROM. This convenient UEFI update tool allows you to update system UEFI without entering operating systems first like MS-DOS or Windows. Just save the new UEFI file to your USB flash drive, floppy disk or hard drive and launch this tool, then you can update your UEFI only in a few clicks without preparing an additional floppy diskette or other complicated flash utility. Please be noted that the USB flash drive or hard drive must use FAT32/16/12 file system. If you execute Instant Flash utility, the utility will show the UEFI files and their respective information. Select the proper UEFI file to update your UEFI, and reboot your system after the UEFI update process is completed"
The above entry was from your mobos manual page 52 ftp://europe.asrock.com/Manual/FM2A88M%20Pro3+.pdf
So you just have to download the instant flash version of your mobo, i believe it is the first file
ASRock > FM2A88M Pro3+ put the file in a fat32 usb disk, reboot, enter bios and follow the instant flash instructions.
I hope this helps.