No, I'm still firmly wedded to 32-bit. I understand 64-bit may get me a teeny bit better performance but at the cost of various peripherals being driverless.
49GB on the C-drive? Is that JUST the Windows operating system, plus a few bits? Seems a lot. Can you copy some stuff off to another drive (datafiles, for example, or Word and Excel documents)?
If the drive really is 49GB and is full, that may explain the strange behaviour.