Having recently moved the DAW to a new computer, in the process of re-installing my software, I realized that I had to install almost as many pieces of software just in order to run the stuff I've paid for. That was enough to prevent me from re-installing 3/4 of what I bought in the last 4 years...
 
Seems practically every manufacturer has his own piece of junk which they force down you throat. This being a new machine, I'm being very conscientious of every little thing I install because I don't want to mess with a lean and highly efficient install.
 
I remember how my previous computer seemed to get slower after I installed the SSL Duende stuff and their gosh darned Code Meter authorization software. Then it was Pace, to authorize Pro Tools and McDSP.
 
Some others don't seem as invasive, like IK's Authorization Manager and NI's Control Center, while Steinberg/Arturia's eLicenser sits somewhere in between. Oh, did I forget Wave's new authorization software? How about Line 6's Monkey?
 
And at some point, you realize that booting up takes a lot longer than it used to, and that what used to be a clean machine is a clutter of software that does not serve you or your purpose, but only the manufacturer - giving them a 100% illusionary impression that piracy is being eradicated.
 
They are using your computer's ressources for their purpose.
 
Man, I wish manufacturers would be forced to come to their senses and cease to behave so carelessly, with so little regards for their customers... We'd need a unified copy protection scheme, or a selection available to the user.

Couldn't agree more.  My last non-DAW computer move probably consumed 16 hours.  Setting up my music computer last time (having moved to W7 64-bit from XP about three years ago) probably took in excess of 40 hours.  The process started making iLok look a lot more palatable ... but I got over that.
 
If just a handful of the major players like IK, Waves, Steinberg, etc. would get together and come up with an effective, customer-friendly, non-dongle (or dongle-optional) universal-registration technology (one that also was free or very low-cost to use by small developers), pretty much every other vendor/developer would want to join the initiative or they would start to lose business.  That sort of thing worked once and gave us MIDI.  It really could work again if the industry could be persuaded it would be good for all, including the vendors.  Name one vendor that has a proprietary registration scheme that doesn't routinely get raked over the goals in the forums by very angry customers.

Exactly.
 
My transition wasn't as painful as yours because I renounced to a lot of plug-ins, and even then it took me a while to get up and running. Though I still get a pop up every now and then when I load a project using a particular EZ library which I have yet to re-authorize...
 
I've re-installed the Waves stuff, the IK stuff, Alchemy, Zeta (thank you Cakewalk for the simple serial number authorization!) the free MiniMoog from Arturia, EZ and SD and Steinberg's Retrologue. That's it. Meaning that most of my plugs were discarded.
 
 
Sometimes, like last night, I find myself wondering whether this or that Kontakt instrument would work in a song, but for now, the authorization process has discouraged me from re-installing. I'd rather find an alternative.
 
Same for iLok - I guess I'll have to go forward with it when I install Pro Tools, but until then, my iLok key is gathering dust on a shelf and my Slate, McDSP and others are not even installed.
 
If just for me, everything could be handled through the store - that would be my preferred method. Just log-in to your account and all your software is there, with all the updates. Hit download and you're done. Then turn off the internet connection until you need an update.

Don't get me started on this.  i have found myself using as computer long past the point where i should be just because  i don't want to go through the pain of moving to a new one.  i think going after known pirates and pressuring governments of countries known to allow piracy would go a longer way towards reduction than making your paying customers go through hell.

A year ago when X3 came out, I installed a new 2T hard drive and went from Vista to W8.1. I did a clean install of X3 64 bit only. I only installed plug ins that I regularly use and left everything else behind. I couldn't be happier with the decision.

That's what I've been doing - but with the price drop on Pro Tools and considering certain opportunities here, I really should upgrade, though that means messing with iLok on my new iMac and I hate that idea. Likewise, I upgraded Slate's RC Tube to VCC today. But I think I won't even install this one before I make the move for PT.

It's been more years now than I would guess since I built my DAW machine.  My goal was to have a lean, fast moving, rock solid recording platform.
 
As I started to consider what I wanted to move from the old lappy over to the new desktop, my guiding light was this:  I move only the things I have actually used in the past 6 months or less.  I considered the things that I used in almost every song and listed them.  I ended up reinstalling only a small core group of plugins. So, lots of things that were on the lappy stayed there and did not get migrated. I have not missed any of them at all.
 
The new DAW was also a completely off line machine. It's only connection comes on the rare occasion when I need to authorize something new. This hasn't even been done in the past 2 years or so. 
 
Has it slowed down any?  IDK....sometimes it does seem slower and others it still seems to boot rather quickly. I never get in a hurry and generally am busy with other things like setting up mics, digging out lyric papers, or some other things..... I let it take the time it needs to boot fully.  Crashes are a very rare occurrence.
 
I also don't attempt to "fix what ain't broken" with it.  I don't worry about cleaning out the directories, I move folders around to storage but beyond that, nope.... I don't mess around trying to optimize it and do other things that generally tend to screw things up rather than make them better.
 
My 2 cents.
 
 
edit:  the machine is based on the Intel i5 chip, 4gig memory running XP pro 32.

Rain, do you have an SSD for your OS/Software? (just thinking about your comment on booting time).....
 
I also have a few of those items they "force down your throat" (IK, NI, Line 6 etc...), but with my SSD, the boot up time is around 10 seconds in getting to the user login screen. After loging in, it takes about 15-20 secs (loading everything in taskbar) and then the DAW is ready to open any particular software.
 
Of course over time, I tend to accumulate more & more stuff which I've noticed the DAW to be slightly slower than when I originally built it (summer of 2013), but nothing significant at all. It's still a very "snappy" and a quick machine when booting up/loading up programs. (DAW is also a gaming/always online/multi purpose machine).     

Nah, just the standard MacBook Pro (and now iMac) drive. But there was definitely a change in boot time pretty much right around the time I installed SSL plug-ins and Code Meter. It went from a couple of seconds to longer and longer.
 
Another mistake I've made is that I've upgraded the OS in order to be able to upgrade some plug-ins. That was definitely the worst idea.
 
Snow Leopard was lean and mean - running Logic 9 on that was essentially my dream DAW. 
 
But starting with Lion and more and more with all the subsequent upgrade, Apple seemed to take a different direction. It used to be that you picked up a Mac off the shelf, installed your software and were good to go. 
 
With the most recent OS, it almost feels like I'm back on Windows - ever since Yosemite came out, my newsfeed is filled with tips on how to optimize OSX, disable this and that. That's somewhat unheard of. It was one area where OSX shone in the past - it could provide you w/ all the eye candy you wanted w/o hindering the performance. 
 
I often had Safari, iTunes, Mail, auto-update all running in the background, I never noticed the smallest issue in Logic. Not so much anymore. As a matter of fact, the last time I worked on the laptop, not only did I close everything but I even turned the Wifi off.
 
My new iMac came with Mavericks installed. I can't complain abut the performance - in fact, I had a big session running last night, with tons of Waves plug-ins, everything running at the lowest latency and the CPU meter didn't even reach 1/4 for even just one of the cores.
 
But that's where it stops. Yosemite will NOT be installed on that computer. Won't be a tough call because I hate it with a passion. I'm starting to believe that Apple hired ex-Microsoft employees to design it. :/
 
If I could, I think I'd buy 20 or 30 new Macs, all running Mavericks, store them somewhere and these would be my future replacements for the studio computer. 
 

I forgot you were on a Mac and sorry to hear about the issues.......I guess it's not always greener on the other side of the fence.