If you're running a build of Windows 7 beta, then time is running out for you. Unless you want to start experiencing reboots and eventually be locked out of the OS, you need to upgrade to the RC (Release Candidate) soon.
Why? Because starting July 1st, users still running a pre-RC build of Windows 7 will start experiencing reboots every two hours. If that's not enough to put a crimp in your day, the come August 1st things take a turn for the worse. This is the date that the OS expires and then you're really stuck.
Microsoft recommended way of upgrading to RC from an earlier build is for users to do a clean install. There's no doubt that this is best option as it completely refreshes your system. However, if this is too much hassle for you then there is a way that you can fool the Windows 7 RC setup files into allowing you to install the update over the top of an earlier build and keep all your apps and settings. My blogging colleague Ed Bott explains how here. I've tested this upgrade path on over a dozen systems and haven't come across any problems at all. Since the RTM code for Windows 7 is now on the horizon, I'm feeling rather unconcerned about upgrading older builds to the RC build in this way.
If you don't have the Windows 7 RC download yet, then you have until August 15th to download it from Microsoft.
Whatever you choose to do, time is running out!