Oh. Yeah, it's quite time-consuming. At least it was for me. Unfortunately, I've never looked into any quick ways to get it done.
Ok, so what was the long way?
I'd like to be able to include going into the BIOS and disabling unused hardware, but it sounds to me like we're dealing with computers that don't really have that ability. I mean, that's usually found on aftermarket motherboards in a computer you built yourself.
So I'll stick to the software layer.
For me, it all started at Black Viper's Service Configurations page for Windows XP:
Black Viper's Windows XP x86 (32-bit) Service Configurations | Black Viper | www.blackviper.com
From there, I kept browsing his site and I found a "Strange Services" page for XP:
Windows XP Strange Service Information | Black Viper | www.blackviper.com
Then, I found a "Super Tweaks" page for XP:
Black Viper’s Windows XP Super Tweaks | Black Viper | www.blackviper.com
This was all a huge help in getting me started with the way I do it today. In a nutshell, I am still influenced by the above guides, but one thing I ended up doing that was pretty different was actually going through each service one by one on his Service Configurations page to read more about it in order to see if I really needed it. I felt better about doing it this way than just going by any of his settings. I actually ended up with fewer processes running in the background by doing it this way.
Then, I opened Task Manager and Googled everything in the Services tab to see what I needed and what I didn't. When I discovered ones I didn't need, I decided to learn how to get rid of them. One of the ways was, of course, by using Services.msc. The other was in the Registry.
So this eventually lead me to three different Registry keys in Windows 7:
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Run
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
I found more than I expected in these keys, so I Googled everything I found in order to see what I needed and what I didn't which resulted in me nearly cleaning them out completely!
Of course, I also made sure that I had absolutely
nothing installed that I didn't need. I even went through and turned off all of the Windows Features that I know I don't need.
I also had a few things in my System Tray (now known as the Notification Area, of course) that I felt didn't need to be there, so I figured out how to make those no longer start with Windows as well.
The end result was that I had a noticeably shorter startup time! I also had a lot less Processes running according to Task Manager (as shown in its status bar). Remember though, I also disabled unnecessary parts of my motherboard in the BIOS, but y'know, I think the software tweaking may have made the biggest difference to my startup time.
So yeah, this was extremely time-consuming, especially going through each service one by one like that. Although of course, Googling everything and doing all that reading was almost equally time-consuming! I'll tell ya though, it was all worth it.
Now that I've typed all this up, I think I remember even going through Services.msc and Googling everything that was either Started, set to Automatic, or set to Manual (some things weren't started even though they were set to Automatic or Manual). This probably helped me get rid of even more things.