Hi Cindy,
The instructions you received from Abydos will work
quite a bit of the time, but unhappily, in the course of creating efficient protocols for installing the operating system on mass produced computers, manufacturers have experimented with a wide array of "partial" back-up files that were hoped to be sufficient for the average user. More unhappily, the manufacturers have a bias for maintaining a dependency of their customers upon the original manufacturer and manufacturer's help resources, whether paid or free. As a result, many pre-loaded systems contain i386 folders that are only partially populated with the supposedly necessary reinstall and backup replacement original files.
Happily, there is a "workaround". SFC will operate with "any" XP installation CD of the same flavor.
Any XP Home install CD will allow SFC to run a complete scan and replacement of required files for a machine with pre-installed XP Home.
Any XP Pro install CD will allow SFC to run a complete scan and replacement of required files for a machine with pre-installed XP Pro.
If I recall correctly your machine is Media Center 2005 (?)… An XP Home install CD would be the one to use if that is correct.
You can "borrow" the appropriate XP installation CD, and then run SFC.
Or you can follow the instructions in the article linked below to create a fully populated i386 folder onto your hard drive.
To put your SFC into action Read and follow the instructions here:
http://www.updatexp.com/scannow-sfc.html
Since you have demonstrated a remarkable tenacity and ability to work independently, I'll leave you with the above instructions and trust that you will post back in case of additional need.
Best Regards
p.s. It may also be the case, that you will be able to obtain an Installation CD from your computer manufacturer directly.
Compaq/HP typically charges $30 US for such a disk.
I'd be inclined to call your computer manufacturer and "talk real tough" with them.