how can we check the current SharePoint Installation type?

Here are the steps:

1. Launch regedit.exe
2. For MOSS 2007, navigate to:
   HKLM\SOFTWARE\Microsoft\Shared Tools\Web Server Extensions\12.0\WSS
3. For Sharepoint 2010, navigate to:
   HKLM\SOFTWARE\Microsoft\Shared Tools\Web Server Extensions\14.0\WSS
4. Check the ServerRole key

Here are the valid values:

• SINGLESERVER => Stand Alone
• APPLICATION => Farm Complete
• WFE => Web Front End