Hi there, it's Jack at Dyson.
Are you able to confirm whether your DC07 includes the brush control feature or not? The brush control would be a round dial on the cleaner head which allows you to turn off the brush bar when cleaning hard floors or delicate rugs.
If your DC07 does include brush control, make sure that when the vacuum cleaner is turned on and reclined, the brush control is set to 'Carpets'. The brush bar will never rotate when the brush control is set to 'Hard floors', or when the machine is standing in the upright position.
If you're confident your machine is already set correctly but the brush bar is still not rotating, or if your DC07 is a version which doesn't include the brush control feature, we'd appreciate the opportunity to provide further assistance.
I'd encourage you to give the Dyson Customer Helpline a call when you have your DC07 easily to hand so we can take you though some simple troubleshooting checks. You can reach us by calling 0800 298 0298 (UK), 1-866-693-9766 (US), 1-877-397-6622 (CA) or 1800 239 766 (AU).