Re: PC will not read DVD+R Discs HELP!
Under control panel>system>device manager: Are there any abnormalities visible when you expand the CD/DVD drives tree? Try to open the properties menu for each device (right click, properties i believe? it has been a while since I have been on a windows machine). There should be a few tabs at the top for each device, does anything out of the ordinary appear, such as a message or warning?
Is the problem limited to DVDs or CDs as well? And if DVDs only, how often do the "normal" DVDs cause you problems?
How long have you been aware of this problem? You mention this has never happened before, so I am assuming these drives both worked normal up to a certain point? Can you recall that point and attempt to think of any major/minor changes you made to the system on or around that period? I.e. new hardware, service package upgrade etc.
If possible, can you attempt to boot from a live-OS and see if the problems remain a constant under a different operating system? I would suggest knoppix. I would try to boot from usb first and see if the OS will allow reading of DVDs, and then perhaps move on and attempt to boot from a DVD.
One last thought, I once purchased a bad batch of CDs long long long ago. I was under the assumption my burner was at fault, as the burning process failed time and time again. Needless to say, after the problem persisted with a new burner, I tried a blank CD from a different source and everything was fine. Basically, have you tried a good assortment of DVDs?