If you think about partitioning by [BeginDate] you should have at least an index on it.

For a start...

It's better to have it as a clustered index, but it's only if you're closed for the long weekend and you can afford a downtime for reconstructing the table with all its indexes.

For now - create an simple 1 column non-clustered index on [BeginDate] and try these 2 queries:

SET STATISTICS IO ON

SET STATISTICS TIME ON

SELECT TOP 2000 * from dbo.xactControlPoint T (NOLOCK)

WHERE beginDate BETWEEN '2014-11-01' AND '2014-12-01' -- = '45409114'

SELECT TOP 2000 *

FROM dbo.xactControlPoint T

INNER JOIN (

SELECT MIN(xactControlPointID) FromID, MAX(xactControlPointID) ToID

FROM dbo.xactControlPoint WITH (INDEX ([IX_xactControlPoint_beginDate]))

WHERE beginDate BETWEEN '2014-11-01' AND '2014-12-01'

) F ON T.xactControlPointID BETWEEN F.FromID AND F.ToID

WHERE beginDate BETWEEN '2014-11-01' AND '2014-12-01'

SET STATISTICS IO OFF

SET STATISTICS TIME OFF

I used (nolock) on the first query not to put you into a trouble for making the table inaccessible for others.

You surely won't need (nolock) for the second one.