PIII faster than duo core processor?

I ran AVG virus scan on my PIII thinkpad laptop with 586MB RAM, and on my Dell optiplex desktop with duo core processor (2.8ghz) and 2GB RAM. I started the scan on the desktop first, and then the laptop. The laptop had scanned more files in a shorter period of time!!!!! How is this possible????confused

 

I'd say the P111 has smaller files. Both running XP?

 

My desktop runs windows media center, and my laptop runs xp home.

 

The desktop has larger files or morew compressed files on the drive. THose take much longer to scan. It could be hard drive speed and such, but I doubt it, in this case.

 

I have compressed files on the desktop, possibly the laptop, before I learned that it slowed it down. I wonder how I might uncompress every file. I uncompressed the windos folder.

 

Could it be the hard drive speed in combination with the size of the HDD? Although my laptop hard drive is slower, it is also much smaller. 20GB vs. 144GB

 

Oh yeah, I have those large video files for the TV shows I recored.