See my previous post...

EXEC MASTER.sys.sp_testlinkedserver @server;

There's a good post by Dave Smith below:

http://forums.databasejournal.com/showthread.php?3090.html

I think this will help with what you need

Is there any chance these jobs were created on a 64-bit server? If so, please check this link: http://www.sqlservercentral.com/Forums/Topic737169-148-1.aspx#bm1420339

If this is a critical process, consider using MASTER.sys.sp_testlinkedserver @ServerName to check the availability of the server before you run your process(es). You could make a function or procedure...

How was the linked server ADSI configured?

How many columns are in this "large" table?

SELECT * (2 or 3 columns) FROM TABLE will run quite well most of the time, whereas if you have dozens of columns...

Do they have to have access to the data source int he report builder? Can't you force it to use one and remove their permissions to view it altogether?

There is an option to "hide" the data source in the list view (I believe you drill down to it via properties when you view the "Show details"). As...

You can't govern the log file growth - this is a logged operation. How "wide" is the index? i.e. How many columns are in it and how many...

While anything is possible, No.

Is this a non-clustered index?

This is a duplicate post

http://www.sqlservercentral.com/Forums/Topic1485438-391-1.aspx

Please ensure:

1. Install Office 2007 Data Connectivity Components (http://www.microsoft.com/download/en/confirmation.aspx?id=23734)

2. Change the extension of your excel file to the proper extension (Ex: .xlsx)

3. Enable "Ad Hoc Distributed Queries" on the server...

High CPU isn't the catch-all for things running slowly. I side with Sean on this one - what makes you think it's SQL?

If you do suspect SQL, then consider...

Is this going to be running via an Agent job or something?

Query looks ok, but I would try adding a WHERE ObjectCategory = 'Person' or whichever you need

I would also try setting the security context to your authentication just to be...