There are 32-bit and 64-bit version of all of SQL Server 2000, 2005 and 2008.
The 64-bit version of SQL Server 2000 is for database services only, most other components run only at 32-bit.
There are some 64-bit restrictions in SQL Server 2005 - the main one I know of is that AMO (Analysis services Management Objects) run only in 32-bit but can manage a 64-bit instance of SSAS. Also, last time I looked I could not find a 64-bit version of SQL 2005 Express with Advanced Services on the MS download site.
There are no 64-bit restrictions with SQL Server 2008 that I know of.
Original author: https://github.com/SQL-FineBuild/Common/wiki/ 1-click install and best practice configuration of SQL Server 2019, 2017 2016, 2014, 2012, 2008 R2, 2008 and 2005.
When I give food to the poor they call me a saint. When I ask why they are poor they call me a communist - Archbishop Hélder Câmara