Optiarc DVD RW AD-7170A

I have two peoblems.

The first and more irritating one is that it reads 3/4 of full DVDs as blanks. I repeat not all of them but the majority. It wasn’t always like this. Last summer I bought a new computer and the guy at the store put into the new one this DVD-Rom and the hard drive from my previous computer. I never had this kind of problems before.

The second problem occured while burning. I was burning a DVD and it reported an error. Now it works really slow. It burns a DVD in 50 minutes, copying files from a DVD takes ages and while I do one or the other everything slows down. I can’t watch movies, can’t listen to music, can’t do anything.

Welcome to the forum.
In Windows device manager, section IDE Controllers.
Check that the port to which the AD-7170A is connect to is in UDMA mode and not stuck in PIO mode. Also check that the IDE cable connecting the drive is an 80 conductor type, and not a 40 conductor cable.