Real happiness is a fresh XP install after Vista!
When my Lenovo T61 laptop (T8300 Core 2 Duo / 2GB Ram) was supplied new last year it came installed with Vista Business. Performance was so inferior to my T42 single core laptop with 2GB RAM and running XP Pro that had preceded it, and Cisco VPN so unstable, that I asked the IS team to install XP Pro instead.
When it came back, performance was far better than with Vista, but still no better than the T42. Not quite what I expected given the same operating system and service pack level but a much better headline tech spec.
From the outset of having XP installed the T61 would not read some types of DVD, and this came to a head recently when I had reason to need it fixed. Despite installing the latest full K-lite pack and being fully up to date with MS and Lenovo patches it still didn't work, so I asked the IS team to reinstall XP Pro, check if it was fixed, and if necessary then troubleshoot it.
When it came back this time the performance was exactly what I would have expected in the first place. To use a manner of speech, a flying machine. The DVD problem was fixed, too.
I asked the IS team what they had done differently this time; the answer was to reformat and install XP. Last time, I learned, they downgraded from Vista to XP per the option that the laptop had been purchased with. I wish I'd known at the time as I would have specifically asked for a reformat and clean installation but right now I'm kinda glad the DVD problem cropped up (which for the record had been solved simply by reinstalling XP)