This week we are continuing our series on tips, tricks and secrets to help you get the most out of Windows7.  This week it's 5 through 11 of 50 total trips.

5. Startup repair
If you've downloaded Windows 7 (and even if you haven't) it's a good idea to create a system repair disc straight away in case you run into problems booting the OS later on. Click Start > Maintenance > Create a System Repair Disc, and let Windows 7 build a bootable emergency disc. If the worst does happen then it could be the only way to get your PC running again.

6. Take control
Tired of the kids installing dubious software or running applications you'd rather they left alone? AppLocker is a new Windows 7 feature that ensures users can only run the programs you specify. Don't worry, that's easier to set up than it sounds: you can create a rule to allow everything signed by a particular publisher, so choose Microsoft, say, and that one rule will let you run all signed Microsoft applications. Launch GPEDIT.MSC and go to Computer Configuration > Windows Settings > Security Settings > Application Control Policies > AppLocker to get a feel for how this works.

7. Calculate more
At first glance the Windows 7 calculator looks just like Vista's version, but explore the Mode menu and you'll see powerful new Statistics and Programmer views. And if you're clueless about bitwise manipulation, then try the Options menu instead. This offers many different unit conversions (length, weight, volume and more), date calculations (how many days between two dates?), and spreadsheet-type templates to help you calculate vehicle mileage, mortgage rates and more.

Don't take any Windows 7 applet at face value, then - there are some very powerful new features hidden in the background. Be sure to explore every option in all Windows applets to ensure you don't miss anything important.

8. Switch to a projector
Windows 7 now provides a standard way to switch your display from one monitor to another, or a projector - just press Win+P or run DisplaySwitch.exe and choose your preferred display. (This will have no effect if you've only one display connected.)

9. Get a power efficiency report
If you have a laptop, you can use the efficiency calculator to get Windows 7 to generate loads of useful information about its power consumption. Used in the right way, this can help you make huge gains in terms of battery life and performance. To do this you must open a command prompt as an administrator by typing 'cmd' in Start Search, and when the cmd icon appears, right-click it and choose Run as administrator.

Then at the command line, just type in 'powercfg -energy' (without quotes) and hit Return, and Windows 7 will scan your system looking for ways to improve power efficiency. It will then publish the results in an HTML file, usually in the System32 folder. Just follow the path it gives you to find your report.

10. Understanding System Restore
Using System Restore in previous versions of Windows has been something of a gamble. There's no way of telling which applications or drivers it might affect - you just have to try it and see.

Windows 7 is different. Right-click Computer, select Properties > System Protection > System Restore > Next, and choose the restore point you'd like to use. Click the new button to 'Scan for affected programs' and Windows will tell you which (if any) programs and drivers will be deleted or recovered by selecting this restore point.

11. Set the time zone
System administrators will appreciate the new command line tzutil.exe utility, which lets you set a PC's time zone from scripts. If you wanted to set a PC to Greenwich Mean Time, for instance, you'd use the command

tzutil /s "gmt standard time"

The command "tzutil /g" displays the current time zone, "tzutil /l" lists all possible time zones, and "tzutil /?" displays details on how the command works.

More next week!