Unfortunately I only attended the first week of a computer building course .....
and
A Pentium (R) 4 3.20Ghz
or
B Intel Dual Core 1.8Ghz.
Exactly how many years ago did you attend this course ?
Both processors are somewhat past it for current needs.... if forced and had absolutely no other choice I'd choose the Dual Core..... the right place for a Pentium 4 is the bin*.
*=Well, a recycling bin of course, collected by a designated WEEE contractor. 