What is App Attach in Azure Virtual Desktop?

App Attach is a way to deliver applications to AVD session hosts without installing them. The app is packaged as MSIX, Appx or App-V, stored as a disk image on a file share, and mounted and registered for a user when they sign in. The app runs from the image and leaves nothing on the host's OS disk when the user signs out.

What is the difference between App Attach and MSIX app attach?

MSIX app attach is the original feature: a package is added to a host pool and every user on that pool gets it. App Attach is its replacement: packages are Azure resources assigned to users and groups through application groups, one package can serve several host pools, and multiple versions can exist at once. Microsoft recommends App Attach for new deployments.

Should I use App Attach or WinGet to deploy apps to AVD?

Use WinGet for mainstream apps that everyone needs and that update often, such as browsers and PDF readers: they install silently from the catalog and patching never touches the image. Use App Attach for apps that only some users need, once you have confirmed they package and run cleanly. Keep agents, Office and anything with drivers or services in the image.

Which apps can't be delivered with App Attach?

Anything with a driver, a Windows service, a kernel-mode component or a per-machine licence, and most apps that write to their own install folder. Microsoft 365 Apps and Teams are installed in the image. Shell extensions and COM components need testing case by case.

Does App Attach reduce logon time?

No. It adds a mount and a registration at sign-in for each attached package, so a slow or distant file share shows up as a slower logon. Keep the share in the same region as the hosts, use CIM images, and watch sign-in times as you add packages. If logons are already slow, see Why are Azure Virtual Desktop logons slow?.

Can I use all three approaches on the same host pool?

Yes, and most estates do. A typical pooled host has agents, Office and Teams in the image, browsers and utilities installed by WinGet at provisioning, and one or two departmental apps attached at sign-in for the groups that use them.

Does Atlas AVD package apps for App Attach?

No. Atlas keeps a registry of the App Attach packages you have already built, including their paths, versions, certificate expiry and state, and it manages WinGet installs and golden images from the same console. Packaging stays with the MSIX Packaging Tool or your vendor, and assigning packages to users and groups is done in Azure.

App Delivery on AVD: App Attach vs WinGet vs Baking Apps Into the Image

Every app on an Azure Virtual Desktop host gets there one of three ways: baked into the golden image, installed at deploy time with WinGet, or mounted at sign-in with App Attach. This guide compares the three on image size, update speed, isolation and licensing, explains what changed from MSIX app attach to App Attach, lists the apps that don't package well, and gives a decision matrix by app type.