I'm making a best effort to turn my Windows XP box at work into a usable system. I'm tired of lugging the laptop to the office, and I have neither desk space nor a network connection for it. I've run CCleaner and Defraggler. I used the freeware version of Revo Uninstaller to clear out a lot of applications I no longer needed and couldn't otherwise get rid of.
It is running quite a bit better. The 1.2 GB of RAM helps. Even Linux can be hell on the desktop in 512 MB of RAM, depending on what you're doing. Windows more so.
I run a lot of free, open-source applications in Windows. It would take me a good half-hour to list them all. Then I have a few critical free-as-in-beer apps.
I'm trying to make my environment as OS-agnostic as possible, hoping that XP will get out of the way (i.e. not stall so damn much) and let me work.
This means a whole lot less time running Debian, though I did set up a second machine at home running Squeeze with LXDE to see how that works for me. I still have the Lenovo G555 dual-booting Debian Squeeze (with GNOME) and Windows 7 (for Netflix streaming purposes ...) but am using it a lot less for the time being.