Motherboards are generally the most important parts in building. Always make sure you get a quality mobo (Asus,Abit,MSI,DFI etc...), even if it's at the expense of other parts of your system. I wouldn't touch a SOYO, or any motherboards less than $80 unless its a brand name I'm comfortable with (see above).
I was gonna suggest you try another Windows XP CD-ROM(get a friend's, don't buy if you already bought), since most downloaded from the internet are corrupted.
I know I've gotten errors during installation from XP CD's downloaded from the internet...I don't remember if they were CRC errors though.
In conclusion, ignore no name motherboards, RAM, and other system components..
They're no name for a reason