Know SharePoint versions

Find out the SharePoint version(standard or enterprise) without the help central administration site.
(This is generally useful when you have installed SharePoint and not run the configuration wizard) At this point in time if you need to know the SharePoint version installed used the below approach

1. Get the SKU
2. Map it to the table.

Step1:
The keys are available in the registry in the below location 

Registry path :HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\Web Server Extensions\14.0\WSS\InstalledProducts\

Could also use power shell to retrieve the same: Get-SPFarm | select Products 

Step2:
Map the key to the table below to know the SharePoint version.

84902853-59F6-4B20-BC7C-DE4F419FEFAD	Project Server 2010 Trial
ED21638F-97FF-4A65-AD9B-6889B93065E2	Project Server 2010
BC4C1C97-9013-4033-A0DD-9DC9E6D6C887	Search Server 2010 Trial
08460AA2-A176-442C-BDCA-26928704D80B	Search Server 2010
BEED1F75-C398-4447-AEF1-E66E1F0DF91E	SharePoint Foundation 2010
1328E89E-7EC8-4F7E-809E-7E945796E511	Search Server Express 2010
B2C0B444-3914-4ACB-A0B8-7CF50A8F7AA0	SharePoint Server 2010 Standard Trial
3FDFBCC8-B3E4-4482-91FA-122C6432805C	SharePoint Server 2010 Standard
88BED06D-8C6B-4E62-AB01-546D6005FE97	SharePoint Server 2010 Enterprise Trial
D5595F62-449B-4061-B0B2-0CBAD410BB51	SharePoint Server 2010 Enterprise
926E4E17-087B-47D1-8BD7-91A394BC6196	Office Web Applications 2010