I've always found it difficult to remember where all the folders SharePoint uses are and what each folder is used for. So here's my attempt to consolidate this information in one post for easy reference. This post assumes default folder locations. Obviously if you customized anything, then you're on your own.

 

WSS/SharePoint Server Program Folder

C:\Program Files\Common Files\Microsoft Shared\web server extensions\12

C:\Program Files\Microsoft Office Servers\12.0 (not sure about this)

This is where most of the program files for SharePoint live.

 

WSS/SharePoint Binaries

C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\BIN

This contains the executable binaries used with SharePoint. For example, stsadm.exe and the WSS Timer service, owstimer.exe, is located here.

 

WSS/SharePoint Server Assemblies, ASPX, ASMX

C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\ISAPI

Contains most of the ASPX (ASP.NET Web Forms) and ASMX (ASP.NET Web Services) files of SharePoint. Also if you are writing code that uses the SharePoint assemblies (ie. Microsoft.SharePoint.dll, Microsoft.SharePoint.Server.dll, ...), then the assemblies you need are located in this folder.

 

SharePoint Logs

C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\LOGS

SharePoint told you to check the logs? This is where you can find the raw log files.

 

SharePoint Site Features

C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\TEMPLATE\FEATURES

Looks like this is where all the SharePoint Features metadata is stored.

 

Site Layout Template

C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\TEMPLATE\LAYOUTS

This is the folder where the virtualized _layouts path for each site URL is located. Add additional files in here to have it be available to all sites.

 

SharePoint Setup Cache

C:\Program Files\Common Files\Microsoft Shared\SERVER12\Server Setup Controller

Looks like this is where SharePoint Setup stores the setup configuration. If you have Office installed as well, then this folder is also used for them.

 

Web Application Virtual Directories

C:\Inetpub\wwwroot\wss\VirtualDirectories

The folder where your SharePoint web applications point to.

 

Web Application web.config

C:\Inetpub\wwwroot\wss\VirtualDirectories\[web application]\web.config

Need to customize the web.config for a particular web application? This is the web.config that you want to edit. Replace [web application] to your web application first of course.

 

Install Web Parts per Web Application in here

C:\Inetpub\wwwroot\wss\VirtualDirectories\[web application]\_app_bin

Additional assemblies (ie. custom web parts) are installed here on a per web application basis. You can also install Web Parts to the GAC as well to be accessible in all web applications on the server.

 

This post compliments my post on SharePoint 2007's registry locations.

If anyone knows of any other interesting folder locations, let me know so I can add them here.