Page 1 of I can`t erase my DVD+RW discs!

I had a Philips DVD recorder which had so many defects I received a full refund. I now have DVD recording software preloaded on my new computer and I should be able to copy video,files,data etc onto my DVD+RW discs. However, I cannot erase the brand named discs (HP,Sony,Philips). Strangely enough, I can easily erase the few unbranded cheap DVD+RW discs I have. "Veritas Record now" is the software loaded which has an "Erase disc" facility but it only works on the cheaper discs. Can anyone please advise if there is an alternative method of erasing data off DVD+RW discs as I am presently unable to make use of the numerous discs I bought originally for use on the Philips DVD recorder. Many thanks
JimK