SQL Server 2008 in-place upgrade gotchas

Here is a list of things to keep in mind when doing an in-place upgrade to SQL server 2008:

• An in-place upgrade does not offer the granularity to pick and choose components to upgrade. For example, if you have your database engine and reporting services on the same box, SQL Server setup will upgrade both the components, so you can't choose one to upgrade leaving the other. If you have such requirement, please do a side-by-side upgrade.
• Upgrading from a 32 bit instance of SQL Server 2000/2005 to a 64 bit instance of SQL Server 2008 using in-place upgrade is not supported.
• In-place upgrade does not support all the paths between editions, for example you can't upgrade from a standard edition of SQL server 2000/2005 to an enterprise edition of SQL server 2008 or vice versa.
• If you are doing an in-place upgrade from SQL Server 2000 to SQL Server 2008, the service pack level on SQL Server 2000 should be SP4.
• An in-place upgrade will fail if you have renamed the SA account. So before doing the upgrade, be sure to rename the SA account back to SA.
• If you are doing an in-place upgrade from SQL Server 2005 to SQL Server 2008 and you are on Windows 2008 server, the service pack level on SQL Server 2005 should be atleast SP2. If you are not on Windows 2008, then SQL Server 2005 RTM or a later version will be fine.
• If you are doing an in-place upgrade from a 64 bit SQL server 2000 to SQL Server 2008,  don't be surprised to see that the management and development tools(SSMS, BIDS etc) are not installed. You will have to rerun the setup again to install them.