The first approach is to open a web browser and got to the site settings page
(Site Actions > Site Settings > Modify All Settings).
The second approach is against the databases. Open SQL Server Management Studio, Connect to the server, new query, run the following:
Use Sharepoint_ConfigDb
SELECT *
FROM Versions
WHERE VersionId = '00000000-0000-0000-0000-000000000000'
ORDER BY Id DESC
This returns (columns reduced for readability):
VersionId Version Id UserName Updates
00000000-0000-0000-0000-000000000000 12.0.0.6219 4 MOSS\user 3
00000000-0000-0000-0000-000000000000 12.0.0.4518 1 MOSS\user 2
The top row is the latest version. The query is performed on the SharePoint Configuration database. If you have called this database something instead of "SharePoint_Config" change the query to reflect this.
You can also look at the versions for Content Databases, by changing the database name. For example: FROM WSS_Content_MySites.[dbo].[Versions]
MOSS Product Version
MOSS 2007 OCT Cumulative update 12.0.0.6331
MOSS 2007 Aug Cumulative update 12.0.0.6327
MOSS 2007 Infrastructure Update 12.0.0.6318
MOSS 2007 post SP1 hotfix KB948945 12.0.0.6303
MOSS 2007 post SP1 hotfix KB941274 12.0.0.6301
MOSS 2007 post SP1 hotfix KB941422 12.0.0.6300
MOSS 2007 SP1 12.0.0.6219
MOSS 2007 October public update 12.0.0.6039
MOSS 2007 August 2007 hotfix 12.0.0.6036
MOSS 2007 RTM 12.0.0.4518
FOR PROJECT SERVER 2007
**************************
Use ProjectServer_Published
Project and Project Server 2007 Hotfix Versions
Number
Release
Server KB
Client KB
4518.1016
RTM
N/A
6061.5000
RTM HF1
935557
6018.5000
RTM HF2
936134
6019.5000
RTM HF3
936517
6020.5000
RTM HF4
936876
6023.5000
RTM HF5
937908
937907
6024.5000
RTM HF6
938189
6026.5000
RTM HF7
938891
938889
6027.5000
RTM HF8
939182
6028.5000
RTM HF9
939594
939595
6218.1000
SP1
936984
937154
6301.5000
SP1 HF1 (Rollup)
941426
941657
6304.5000
SP1 HF2
949398
6307.5000
SP1 HF3
950284
6308.5000
SP1 HF4
950480
6309.5000
SP1 HF5
950816
6310.5000
SP1 HF6
951166
6312.5000
SP1 HF7
951169
6313.5000
SP1 HF8
952000
952067
6314.5000
SP1 HF9
952289
952293
6316.5000
SP1 HF10
953136
6317.5000
SP1 HF11
953478
953476
6318.5000
Infrastructure Update
951297
951547
6327.5000
CU1 - August 2008
956061
956060
6331.5000
CU2 - October 2008
957696
958138
6334.5000
CU3 - December 2008
960313
959643
6341.5002
CU4 – Feb 2009
968271
966308
6422.1000
SP2
953334
953326
6503.5000
Apr 09 CU
968860
969409
*For Project Client you can check from Project Professional >>Help >>About Microsoft Office Project