DNS Issue

I bought a desktop less than 2 months ago, and I'm having a DNS issue from day one.  When the error occurs, it shuts down my internet.  I contacted Dell support, and I was told it is not their problem - nice right?  I called my internet provider, and they said it wasn't their problem either.  So here I sit with a new computer that doesn't work right.  The sad part is that I bought a Dell over a HP because I thought their service would be better - WRONG!!!