Question : Error Code =0x490 on "System Files Integrity Check and Repair Error Code = 0x490"

For some reason, my system hangs up on startup for a long period of time before cycling into Win 7.  Once in Win 7, all systems are a "go."  Then, when I tried a reboot, I got a request to perform a system repair because of the "bad" startup... I tried the repair and got the above error message indicating the error code =0x490... What can I do?  Where should I look.  I have a feeling it may be in the Bios...???  I tried a system restore, because a critical update was installed on my system, by the system last night, but I don't know if that was the cause. Anyway, I restored the system successfully... but the startup process still hangs... and an additional couple of attemts to restore result in Windows cannot fix the problem....

I googled for a solution, and some people had to reinstall their operating system.  One guy just had to identify a hardware conflict, and disable ACPI in Bios.  What would disabling ACPI do?  

Windows 7 Pro
Dell XPS710 Studio

Answer : Error Code =0x490 on "System Files Integrity Check and Repair Error Code = 0x490"

I think you should turn off all additional USB disks if you have them...