The system cannot boot. The file is possibly corrupt. The file header checksum does not match the computed checksum

Well, isn’t that special. This error was greeting my wife when she booted up Windows Vista on her Sony Vaio laptop the other day. This error message comes up directly after BIOS POST, within milliseconds. No chance to enter safe mode, no chance to press F10 for system recovery.

Booting from the Windows Vista DVD, I can enter the command prompt and run CHKDSK with no errors. Even CHKDSK /R doesn’t find anything out of the ordinary. The Repair option doesn’t find anything. Booting from the DVD, pressing F9 and selecting the memory diagnostics, it ran for 5 passes without finding anything. Just great…

As it turns out, one of the memory modules was the culprit. The laptop has one 2GB SO-DIMM module and one 1GB. Removing the 1GB module, the laptop boots up happily as if nothing has happened. Hmm…. wondering why the memory diagnostics didn’t find this.

How to enable database diagram on SQL Server 2008

You have to enable database diagram on SQL Server, otherwise when you try to create a database diagram on SQL Server 2008, you are greeted with this message:

TITLE: Microsoft SQL Server Management Studio
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Database diagram support objects cannot be installed because this database does not have a valid owner.  To continue, first use the Files page of the Database Properties dialog box or the ALTER AUTHORIZATION statement to set the database owner to a valid login, then add the database diagram support objects.

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BUTTONS:

OK
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So, first go to the database properties and select the Files tab. Select a valid login as the DB owner. Then go back to the Database Diagrams folder, right click and select Install Diagram Support. The next dialog show this message:

TITLE: Microsoft SQL Server Management Studio
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This database does not have one or more of the support objects required to use database diagramming.  Do you wish to create them?

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BUTTONS:

&Yes
&No
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Click Yes.

Now go back and create a diagram.