1720 and WIC 1ENET

Hi

Have a Cisco 1720 here and a wic 1enet, the wic is in slot 0 with the OK light green. The IOS won’t pick it up, IOS version number is 12.1 (8a) release fc1, do I have a hardware problem or is the IOS incompatible? Can’t seem to find 8a on Cisco website, any help would be appreciated.

thanks