yes, you made a mistake...
You should have gone with 64-bit to utilise all of your 6GB.
Aside from that most of these comments are driving me nuts:
Aero - Is good if you have a reasonably modern machine, can be switched off for those that don't want the extra fluff.
Taskbar - Not to everyone’s taste however absolutely flexible to have it work in the style of days gone by (XP). Turn off combine, turn-off aero peek and it's the virtually the bloody same!
Search - leaps and bounds ahead of any previous incarnation of windows (obviously not of you turned off indexing). No worse and no better than any other OS in-built system.
Office - you can still run office 2003 if you really want to.
CAD compatibility - maybe it's time to upgrade after running the same version for the last 10 years! In all seriousness, there are old and legacy applications that aren't 'supported' however will work after tweaking with the various troubleshooting options.
Explorer - It's called innovation... have you actually tried using the dropdowns in the breadcrumb-ish address bar? Maybe you don't like that? Fine, your choice - if you want that more 'XP' feel go in to folder options and right there on the General tab there are two options for the navigation pane, namely 'Show all folders' and 'Automatically expand to current folder' - turn them on. No need for 3rd party software for that.
There are literally a hundred reasons corporations should look to upgrade to Win7 and any decent administrator that works at a company which runs windows would agree from a security & administrative stand-point.
Time to move on and stop being a luddite!