What is the equivalent of MS Access InStr function in SQL Server 2008? This query runs in Access 2013 but I need it converted to SQL Server 2008. The issue is that the INSTR() function does not exist in SQL Server and the query references the field generated in same query EXPR1.

How would this be changed over to SQL Server 2008?

SELECT PartID, Description, Service, 
InStr(1,[Description]," ") AS Expr1, 
Left([Description],[Expr1]) AS part
FROM TI
WHERE (((PartID) Is Not Null) AND ((Service)="JTP"));
InStr is pretty similar to CHARINDEX. So, your query can be written as:

SELECT  PartID, 
        [Description], 
        [Service], 
        CHARINDEX(' ',[Description]) Expr1,
        LEFT([Description],CHARINDEX(' ',[Description])) Part
FROM TI
WHERE PartID IS NOT NULL 
AND [Service] = 'JTP';