You install an audio plugin on Windows by putting it in a plugin folder, and most of the time an installer does that for you. The confusion is that only one format has a fixed folder, Windows can block the installer before it even runs, and when a plugin does not appear there is no error telling you why.
Paths shown are for 64-bit Windows, which is what modern hosts use. Where a plugin format or a host behaves differently, it is called out. If you are on a Mac, the macOS version of this guide is the one you want.
Windows gives just one plugin format a fixed, guaranteed folder, and that is VST3. VST2, the older version, has no standard folder at all, and AAX has its own. An installer drops each file into the right place for you. If you are copying a plugin in by hand, these are the folders a host reads.
| Format | File extension | Folder it installs to |
|---|---|---|
| VST3 | .vst3 |
C:\Program Files\Common Files\VST3 |
| VST (the older VST2) | .dll |
No fixed folder. You pick one and point your host at it |
| AAX (Pro Tools) | .aaxplugin |
C:\Program Files\Common Files\Avid\Audio\Plug-Ins |
VST3 is the easy one. Steinberg, who created the format, defined a single mandatory path for it, so every VST3 plugin belongs in C:\Program Files\Common Files\VST3 and every host already knows to look there. Drop a .vst3 in that folder and you are done.
VST2 is where Windows gets messy. The old format never defined a location, so a .dll can sit in any folder you like. Common choices are C:\Program Files\VSTPlugins, C:\Program Files\Steinberg\VSTPlugins, or C:\Program Files\Common Files\VST2. The folder itself does not matter. What matters is that your host has been told to scan it, which is a step you set once inside the host. Pick one VST2 folder and point every DAW at the same one, or you will end up with plugins scattered and half of them missing.
AAX is for Pro Tools and Media Composer only. It has a fixed Avid folder, and nothing but those Avid apps reads it, so an AAX file is no use to any other DAW.
Audio Units, the .component format, is Apple's own and exists only on macOS. There is no version of it for Windows and no setting that adds one. If a Mac developer sells you an AU and nothing else, it cannot run on a PC. On Windows the formats that exist are VST3, the older VST2, and AAX for Pro Tools. When you buy, the one that works almost everywhere on Windows is VST3.
If the plugin came with an installer, use it. It puts the VST3 into C:\Program Files\Common Files\VST3 and any AAX into the Avid folder, and it asks for permission to write to Program Files. That is the User Account Control prompt, the one that dims the screen and asks Yes or No. It is normal, not a security problem.
If all you have is the raw plugin file, copy it in yourself. A .vst3 goes into C:\Program Files\Common Files\VST3. A .dll goes into whatever VST2 folder your host is set to scan. Open File Explorer, paste the folder path into the address bar at the top, press Enter, and drop the file in. If the folder does not exist yet, create it with exactly that name.
Quit your DAW before you install. Hosts scan for plugins only when they launch, so anything you add while one is open will not appear until you fully quit and reopen it. And if the plugin arrived as a .zip, unblock it before you extract, which is covered in the next section. Those two steps account for a lot of "it did not install" reports.
One more thing to match: the build. Modern Windows and modern hosts are 64-bit, so install the 64-bit version of the plugin. VST3 is always 64-bit, so this only comes up with old VST2 .dll files, where a 32-bit one may not load into a 64-bit DAW at all.
When you run a plugin installer, Windows may show a blue box that reads "Windows protected your PC" and appears to give you no way forward. That is Windows SmartScreen. It shows up when you run an installer Windows does not yet recognise. It does not mean the plugin is broken or infected. It means the installer is either unsigned or simply new, so it has no reputation built up with Microsoft yet.
To get past it, click the small More info line in that box. A Run anyway button appears underneath. Click it and the installer runs as normal. Only do this for a plugin you downloaded from the developer's own site or store, which is the same care you would take with any download.
If the plugin came as a .zip, unblock the zip before you extract it. Right-click the downloaded .zip, choose Properties, and at the bottom of the General tab tick Unblock, then click Apply. Windows tags anything downloaded from the internet with what it calls the Mark of the Web, and when you extract a still-tagged zip it copies that tag onto every file inside. A host can then quietly refuse to load the plugin, or the installer keeps getting blocked, for no reason you can see. Unblocking the zip once, first, saves doing it file by file later.
The host scans for plugins at launch and lists only the ones it can find and load. A plugin in the wrong folder, or in a folder the host was never told to scan, is simply absent, with no message. Work through these in order.
Hosts look for new plugins only when they start. Installing one while the app is running does nothing until you quit and relaunch. Many DAWs also have a "rescan" button in their plugin settings. This alone fixes most cases.
For a VST3, confirm the .vst3 is actually in C:\Program Files\Common Files\VST3. Paste that path into the File Explorer address bar and look. If it is somewhere else, that is the problem.
This is the Windows-specific one that catches people. Because VST2 has no standard folder, the host will not find your .dll unless you have told it which folder to scan. In your DAW's preferences there is a plugin or VST paths list. Add the folder you put the .dll in, then rescan. If a VST2 plugin is missing, this is almost always why.
Not every host loads every format. There is no Audio Units on Windows, so an AU will never appear. AAX only loads in Pro Tools. Some hosts load VST3 only and ignore VST2 entirely. Make sure the format you installed is one the host actually supports. The formats explained guide covers which is which.
Modern hosts are 64-bit and may not load a 32-bit plugin. If you installed an old VST2 that only came in a 32-bit version, it can be missing for that reason alone. Look for a 64-bit build from the developer. VST3 does not have this problem, since it is always 64-bit.
Once installing is sorted, the question is what is worth installing. If you want instruments that write actual music rather than another folder of presets to trawl through, here is what we make.
The Collection is three of our instruments together, ARGISH, SILT and REHEAT, with three separate licence keys, one per instrument. On Windows each one ships as a VST3, 64-bit, so it drops straight into C:\Program Files\Common Files\VST3, the one folder every host already scans, and none of the folder guessing on this page applies to it.
You do not have to take that on faith. Play one free in your browser first, no install and no account, and hear what it does before you buy anything.
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