Most probably the problem is in the windows communications with the HD. Before disabling SMART reporting, I'd suggest checking to see if there are any new BIOS, HD driver or chipset driver updates for your computer.
Meanwhile, or if there are no updates, get also your own S.M.A.R.T. reporting tool and trust its results. GSmartControl is one such tool. Freeware and allows you to both check current status and perform any built-in tests supported by your HD. This is better than the BIOS page own ad-hoc reporting.
To actually disable SMART, well you do it on the BIOS. You cannot disable it in Windows. I'm not sure what you mean by forgetting how you disabled the reporting in the past. It's possible you know something I don't, but I never heard of anyone able to disable S.M.A.R.T error reporting on windows.