Might try to clear the CMOS. To find your bios version on the post screen it will say something like GA-990FXA-UD7 F1a This is your bios version.
**Edit** After looking at your MB manual there isn't a code 88, however there is a code 8B. Updating your bios to the latest may solve your problem if its related to compatibility. However it may not be that simple.. Looking at your MB on gigabytes web site any bios version below F4 does not support your CPU. F8 is the latest. It is my understanding that you will need a processor that is supported by your bios on board now to flash it to the newer bios. So it looks like it may depend on your current bios version.