Different user accounts have huge difference in performance?

[Reckoning]

I have my administrator account which i use daily and i have a guest account I have for anyone else to use.
My main user account has become very sluggish and I had done a lot to figure out what the problem was. I always keep antivirus software up and running and I use Malware Bytes every so often. Nothing detected so I started piece by piece looking at hardware. Thought I had it all pin pointed to my hard drive because when my computer would be acting up the "DISK" marker for performance resource monitoring would be flipping out.
Recently though I was on my guest account and ran various programs and not only did the programs respond much quicker, windows overall felt much more responsive. Having said all that I know that per user account you have different "startup" applications that run that could affect user account performance but I have almost nothing but bare minimum running at startup.
Even if I am logged on my administrator account and just "switch user" to my guest (so my administrator account is still running in the background) everything runs great. Wouldn't guest be affected by performance in this case since administrator is still running in the background?

 

[gbhall]

Are you sure the administrator account is still running when you switch away? It may be suspended.

You are accurately deducing the number of applications active in different accounts would have an effect

Other things you may not have considered are

network access. Are guest users also using the internet or not?
file quantities. Huge quantities of files in directories accessed by Admin slow things down noticeably. Cache in particular needs cleaning out periodically. See ccleaner app.
logging. Some users are amazed when they discover the logs being left behind by processes they run. One person I helped to spot this was using 25Gb in just logs !!!
Bad HDD spots. areas accessed by admin account may have a lot of recovery action on the HDD. Test with chkdisk and manufacturers test software

 

[DelJo63]

Consider looking for services/programs running as autoupdates.
Using Spybot S&D you can find all the startups AND which accounts they would use to run them. GUEST would only run those started under All Users.

 

[Reckoning]

I see all startup items in spybot s&d however I don't see where it says which users they load under. I looked at startup items on main account then logged off and logged in under guest account and loaded spybot and looked at startup items again there.. it just showed all the same entries.

Other things you may not have considered are

logging. Some users are amazed when they discover the logs being left behind by processes they run. One person I helped to spot this was using 25Gb in just logs !!!

How do you check and clean this?

 

[gbhall]

Downoad and install this http://www.jam-software.com/treesize_free/ or http://www.snapfiles.com/get/treesize.html which will give you a clear picture of where a lot of hidden files may be accumulating. From that, you can usually discover what program is dumping those logs but never cleaning them up. Those type of programs often have a means of reducing or even stopping the logging.

This post is a good example https://www.techspot.com/vb/topic165532.html