For Office 2K. Service Release 1 and 2 need to be installed consecutively, unless you get a fully patched install media with O2K SR-2 compiled in.

That is your major problem. If you update your OS to Service Pack three... do that LAST!

Here is the order in which to install IFFN you gonna Wipe!

W2K - Default install no patches
O2K - Full "Run from HardDisk" install
O2K - SR1 let it do it's thing
O2K - SR2 let it do it's thing
Windows Update get
SP3 first
Then either IE 5.5sp2 or IE 6 sp1
Then all the other "criticals"
DO update to DirectX8.0a as Office uses DirectX now
Don't get Windows Media Player 9... it is FSCK'd with DRM in it now and it seems to have broken Roxio Cd Creator Platinum... GRRR!
Then what ever you want "reccomended" and drivers...

Lotsa work indeed though. You could cut out the Wipe and reload, just make sure you re-apply W2K-SP3.

Have fun!