This can happen even if you are running as an Administrator, and it is caused by Windows very strict security settings.
To fix this, right-click your Visual Site Designer shortcut icon and select Run as Administrator. This should properly launch Visual Site Designer for you. If it does, great! You can continue to launch the program in this way, or you can go a step further and configure the shortcut to always run as administrator. Here's how:
1. Right-click the shortcut icon, and click Properties.
2. Click the Compatibility tab.
3. Here, put a check mark by Run This Program as an Administrator.
4. Next, put a check mark next to Run This Program in Compatibility Mode For: and ensure Windows XP Pro Service Pack 2 is selected.
5. Click OK.
If you continue having problems you may also need to set the application as an exception to Windows Data Execution Prevention (DEP) feature
. Normally if this is the culprit, you'll get a little bubble along the taskbar notifying you, which will allow you to set the offender as an exception.
One last option that could be the cause of this, and related to the DEP feature, is User Account Controls
. This is the large window that appears in Vista asking you to "Allow" or "Deny" access to functions within programs. You can turn this off within your Control Panel > User Accounts window, along the left-hand pane.
All three options let you control your system exactly how you want and give you full access to do/run anything on the computer.