Writing this using IceWeas...
[crashed again - I meant to say, IceWeasel on Knoppix, PC with no HD and 192MB of SDRAM. Predictably, it crashed when I tried to multi-task.]
After a few hours...
It seems I messed up my system, thanks to an unexpected shutdown in the middle of resizing my second hard drive. It scrambled the boot sector, making it unreadable.
I was at a loss on what to do. Thankfully enough, my XP was unscathed (only problem was the loose IDE connector) so I was able to run Paragon Partition Manager Pro. Good for me, it restarted the scripts and my data was where it should be.
Moral of the story:
Make a separate partition for Data (e.g. Installers).
Sandbox installs before committing to a new OS.