Did you forgot your administrator password of your Virtual Machine in Windows Azure?
As of now, there is no way to reset the password externally (outside the VM). To make changed to Azure VM password you would need to have access to Azure VM. But there is a work-around which you can use to get back VM in same state.
Create a new Azure VM and attach old VM as data disk to new VM. Now, you will be able to get access to your old data.
TIP: As password loss could be a significant issue, you can add a new Admin user to your VM after creating the new VM so in case you lost the main password you will still have access to same VM using the other admin user.
Here is the topic created in Feedback Site requesting reset password feature for VMs in Windows Azure. You can vote up for it if you want it in future releases.