DVD-RW - erasing them

Can you help me please?
I bought what I thought was dvd-rw discs. However, the first time I used the disc, it only burned for 4% so I intended to use it a second time but it then said there wasn't enough space on the disc.
How can I erase what is already on there so I can start at the beginning again please? I am using Windows XP/Nero 6. Thanks

 

i never use rewriting disks because if you have 1 bad burn you lose the disk for ever so i do not think there is any thing you can do

 

I can't imagine why a problem burning a DVD-RW or DVD+RW would cause it to totally fail, that hasn't been my experience.

Did you put the disk into the drive and select Erase Re-Writable Media?

 

where is the Erase re-writeable Media option please? perhaps that is my problem as I couldn't find that option in nero. thanks