Hello there - i just recently encountered ATAPI errors in my Win 7 event viewer. The errors say "The driver detected a controller error on \Device\Ide\IdePort2.". At the same time, transfer rates to the hdd in question became very slow. I ran chkdsk /f /r - no issues reported. I also ran the SeaTools for Windows tool - no SMART errors, short tests show also no issues. Currently running the check from EASUS Partition Manager - so far everything green, however, at the same time, the errors in the even viewer keep showing up (while EASUS is running surface check and reporting everything as green...)
Couple things to check: Double click on the Event Viewer error (is this a red exclamation point error?) and it will bring up a an event properties box. That has an online help link which may give you more specific information about the error.
Also, could there be another HDD or Device on this IDePort2 that is not being checked, since you mention transfer rates from another device. Check the BIOS to see what is on Port 2.
A very good testing program is HD Tune (free edition) or HD Tune Pro, which gives you Disk Health Info, S.M.A.R.T. parameters, and you can test the file data transfer rates across the disk. Here's the link
Thanks - HDTune did indeed help me solve the problem. It reported a warning related to a SMART factor that could indicate a bad cable. I checked the MB and the cable in question was indeed loose. After resetting it, no more atapi problems! Its a shame that neither the Seagate nor WD tools reported that issue and showed the SMART status always as green...