SharePoint 2007 can only be installed on the Windows Server family platform. As a developer, I need to be able to develop on this platform. However, my development platform is currently either XP/Vista/7 based running VS 2008. What doesn’t make any sense to me is that all the tools require WSS to be installed locally, on a 2003/2008 Server platform.
The recommendation for MOSS development was always to get a VM to run W2k3 with MOSS and Visual Studio. Ok, so what do you do if you do not have the time to build such a platform, or what if you do not have access to a server OS.
If you try to install the Visual Studio 2008 Extensions for Windows SharePoint Services 3.0 Tools (VSeWSS) on a workstation you’d probably fail and get the following error: “This product can only be installed if Windows SharePoint Services 3.0 has been installed first”. So the only thing we can do is either conform to the VM path, or we can hack the installer into thinking MOSS is installed. We are going to hack!
You might as well make sure to download the latest extensions installer. I installed the Visual Studio 2008 extensions for Windows SharePoint Services 3.0, v1.3 - Feb 2009 CTP on my work machine.
Before continuing into opening the Regedit tool, be aware that messing around with the Windows registry is not supported, and not recommended by Microsoft. However, being a computer nerd, I don't give a poop. I can always fix it 
Now open the regedit. My work environment is running Windows 7, so I have to make sure to open regedit and run as an administrator.
Make a quick backup of the registry, just in case. If you do not know how to do this, Do not pass GO, do not collect $100. Honestly, if you cannot make a registry backup or do not feel comfortable hacking the registry, you probably should not continue. That was my only warning.
Create the following keys and the string value:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\Web Server Extensions\12.0]
"Sharepoint"="Installed"
Tada! Now when we run the installer, the installer has been tricked into believing that we have Sharepoint Services installed locally.
I also recommend adding the SharePoint and MOSS assemblies into the GAC. The assemblies can be found in any SharePoint server under the C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\ISAPI folder.