If I’m an Administrator, Why Do I Get Access Denied?

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UAC logo

User Account Control (UAC) can seem mysterious. After all, if I’m a member of the Administrators group, shouldn’t I have access to everything?  If you’re a developer, you’ll run into a UAC issue sooner or later.  In this post, I’ll cover the basics that every developer should know. Standard User by Default Running applications as…


Q: Why Doesn’t Drag-and-Drop work when my Application is Running Elevated? – A: Mandatory Integrity Control and UIPI

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UAC logo

If you run notepad elevated (Right click | Run as Administrator), and you try and drag-and-drop a file from Windows Explorer, nothing happens. It looks like it is going to work because the pointer icon changes but the file doesn’t open. Weird, huh?   What’s Going On?   In the traditional NT Security model (prior…


Common Problems with Checking OS Versions in Code

When a new OS is released, a high percentage of applications don’t install or don’t run because they check for a specific OS version.  The application or installer checks for a specific version number and exits if it isn’t what is expected. I’ve heard claims of up to 50% of incompatibility issues are due to…


Common Issues with 32-bit Applications Failing on 64-bit

In most cases, 32-bit applications execute with no issues on 64-bit thanks to WOW64. However, there are a few cases that you may need to make modifications to your application in order for it to work on 64-bit.  I’ll cover the common issues and possible solutions in this post. 64-bit OS Basics Issue Solution 32-bit…


Tales of Application Compatibility Weirdness – Demystifying UAC Virtualization

We had a customer in the lab recently and they were quite certain their application was Windows 7 ready. To their surprise, it had several issues in certain situations.  In this post, I’ll talk about one of the situations they encountered as well as other stumbling blocks you might run into with UAC Virtualization. Why…


Answers to Several Application Manifest Mysteries and Questions

Recently, someone asked me this question in e-mail — “How do I get my application to run elevated when someone launches it?”   Instinctively, I responded with a “You need to manifest it.”  I got a nice long e-mail in return. 😉 I quickly realized that application manifests appear simple but are quite confusing. Manifests are…


Registering ATL Performance Counters on Vista and Server 2008

If you use the ATL Server performance counter libraries, you may run into a problem on Vista and WS08.  The ATL libraries don’t play well with the updates to Windows Resource Protection.  WRP enforces restrictions on the registry to prevent corruption of performance counters.  ATL breaks these rules and tries to update the registry directly….


Windows Server 2008 Application Compatibility presentation

In the compatibility labs, we always give an big overview presentation about Windows application compatibility.  There’s a lot of overlap between Vista and WS08 AppCompat but we call out some specific areas that mostly affect WS08.  We’ve recorded the WS08 specific section of the presentation and posted it to Channel 9.  I hope you find…