Microsoft Windows Vista

"The System Administrator has set policies to prevent this installation"

This very annoying error sometimes occurs when you try to install something or update an existing program on Windows Vista. Searching the web, you'll find lots of advice on what to do if you get this error on a Windows 7 machine, but very little on what to do if you are still using Windows Vista.

• If this is a company computer connected to a giant network, get on to your system administrator. If you yourself are the system administrator, get on to your security adviser and discuss these instructions with them before proceeding.

• If this is your home computer, roll up those sleeves and get stuck in.

First some general advice - concentrate on the task. If there are parts of the following installation where it looks like it might take a minute or two, don't wander off and make yourself a cup of coffee, or start up a browser and check your Facebook status. Keep your eyes on the screen and watch for error messages or unusual behaviour.

Now here's what to do to tackle the problem:

1. Find the exe file that is being run to install the program. This will involve some hunting around. Trying right-clicking on things and checking their properties. One of these may show you the name of the exe file. Use Start / Computer to find the exe once you know its name. Right-click on it and select "Run as administrator". If it is a simple installation, this may be enough to fix the problem. If you continue to get the error message, or if you can't find the exe file to carry out this step, proceed to step 2.

2. Turn off your antivirus program. I haven't found this to be useful, but it is what everybody recommends, so try it before going on to step 3. In most antivirus programs, there's an icon in the bottom right of the screen - click or double-click on this, then select from a menu to disable the program. In Norton Internet Security, for example, the icon is a world on a yellow square with a green tick sign on it. In the advanced settings, you move a lot of slider switches from on to off. There is the option to turn off all checks for an hour. They will start up again after an hour if you forget to turn them back on.

   Once virus checking is turned off, run your install again. Don't do anything else while virus checking is turned off. Don't go and browse your favourite sites, as you may catch a virus. Just confine yourself to installing the program. If the program installs correctly, proceed to step 5 to turn back on your antivirus software. If you continue to get the error message, proceed to step 3.

3. Turn off User Account Control (UAC). This is a part of Windows that watches out for odd programs being run by people who shouldn't. Chances are it is this that is preventing your program from installing correctly.

   • Click Start and then click Control Panel
   • In the Control Panel, click on User Accounts and Family Safety, then click on User Accounts. (If you use the control panel 'Classic View', just double-click on the User Accounts icon.)
   • Click on Turn User Account Control on or off
   • If the warning "Windows needs your permission to continue" appears, click Continue.
   • There's a tickbox with "Use User Account Control (UAC) to protect your computer. Remove the tick from the box and click OK.
   • You'll be given the option of Restarting now or later. Choose Restart now. The computer will restart without User Account Control.

   Now attempt to install your program. If you still get the problem, I can't help you any further. For me, this solved the problem.

4. Whether the program installs or not, you'll need to turn back on the things you've disabled. Start with User Account Control:

   • Click Start and then click Control Panel
   • In the Control Panel, click on User Accounts and Family Safety, then click on User Accounts. (If you use the control panel 'Classic View', just double-click on the User Accounts icon.)
   • Click on Turn User Account Control on or off
   • If the warning "Windows needs your permission to continue" appears, click Continue.
   • There's a tickbox with "Use User Account Control (UAC) to protect your computer. Tick the box and click OK.
   • You'll be given the option of Restarting now or later. Choose Restart now. The computer will restart with User Account Control enabled, as it should be.

5. Turn back on Antivirus Checking. Even if you selected the option to disable it only for an hour, you should still re-enable it immediately.