One of the handy things that both Windows XP and Windows Vista have as a feature is a built-in de-compression right click function, allowing you to un-zip files that are zipped. It's an unfortunate reality that many people don't understand how ZIP compression works and they ZIP files that are already compressed (such as JPEG and MP3 files), resulting in basically no space savings. Something I've noticed since moving to Vista is how ridiculously slow it is at decompressing ZIP files.
I did a quick test: I took a 318 MB file, compressed it down to 125 MB (so it was 60% compressed) and put a copy on two of my systems: one, an Intel Core 2 Duo overclocked to 2.9 Ghz with Winzip installed, and the other, an Intel Core 2 Duo Extreme overclocked to 3.35 Ghz without Winzip installed. Both systems have 3 GB of DDR2 800mhz RAM installed and both systems are running the OS on 10,000 RPM Western Digital Raptor drives. If the software decompression speeds between Winzip and Vista's decompression were equal, you'd expect the faster 3.3 Ghz CPU to trounce the slower system right?
The 2.9 Ghz system decompressed the 318 MB file in 23 seconds, while the faster 3.3 Ghz system took 33 seconds - that's 43% slower, and it's on faster hardware. I don't have XP installed on any similar hardware, so I can't replicate this test with the older OS, but I don't remember it feeling so ridiculously slow. Is anyone else seeing the same thing?