Able to read DVD+R but not DVD-R

I have always been able to read and write both DVD+R and -R but recently my drive starts to get a bit slow reading DVD-R and eventually it doesn’t recognize it at all.

I have a built in hl dt st dvdrrw gwa 4161b on my acer desktop running win xp. I have tried reformatting with the recovery disk but it doesn’t work.

Have also uninstalled the dvdrw using device manager and have windows auto detect and install d dvdrw but also doens’t work.

Have also tried to upgrade d firmware but somehow something went wrong and d dvdrw appeared as a cd-drive. Hence I did a system restore.

The desktop comes with a default NTI burner and I have uninstalled my nero and did a cleanup and also done lens cleaning using a lens cleaner but still doesn’t work.

What could be wrong… can some kind souls pls help… :sad:

Opps it should be hl dt st dvdrrw gwa 4164b instead …