The essentials

I started the Windows reinstall a couple of days ago (having lost the hard drive I had been booting from).

Having done this I then reinstalled the software I can't live without, which seems to be:

The Bat! (best email client I've used, ever).
Winamp 3 (I actually prefer Winamp 2, but I'm forcing myself in the hope that I'll get used to it)
Microsoft Office (and yes, I do need lots of the extra functionality you don't get in Emacs)
AIM (for those people that don't have MSN. Well, basically for OnceUpon, in the 5 minutes a month we're both logged on)
Adobe Acrobat Reader
AVG Virus Killer (best free antivirus I've found)
Kazaa Lite (I want my, I want my, I want my MP3. And videos. and software. and porn).
Semagic LJ client (so much better than the standard windows one)
Spampal (spam recognition program. Works as a transparent POP proxy and is accurate 95% of the time. The rest of the time I use the built in blacklist-whitelist function)
Metapad (The best notepad replacement I've found).

If anyone has suggestions for essential software I should be using, I'd love to hear them.