MacBook Pro instability over the last few months I have a Mid-2012 MacBook Pro. The last few months my MBP has been very unstable. I must have performed a clean install roughly around 15 times. 
Everything works well right after a fresh install, however, give it a day or two, and it's unstable again. I don't really keep a lot of data on it, just use it mostly for browsing. 

The problems I encounter are stalling, the beachball spinning while I am browsing or typing. A lot of times the beachball just doesn't stop spinning or stalls itself. At this point everything else stops functioning hence forcing me to perform a hard boot.

I upgraded to High Sierra yesterday, and had to do a clean install again today. Before performing the clean install, I tried rebooting in Safe Mode, didn't work. Even if I did manage to log in to the user account, nothing was loading. 

I've performed the disk utility check and all seems fine. At least that's what I think. What am I supposed to be looking for after performing the disk utility check? It doesn't show up with any errors. 

All seems to be working fine with the guest account. However in order to be entirely sure about the guest account, I would have to use it for an extended period of time. I suspect my iCloud account might be corrupted. 

Is it possible for a corrupted iCloud account to cause such instabilities with Mac?
i hate this beachball, but you can do some things, first is to start with cmd+r and go to terminal and write     csrutil disable and reboot. now your sip is disabled and you should  enable it in the same way when your finished with this steps:   


Go to About this    mac under the apple in the upper left and click
on More info
Click on system report
make a note of what it says after Model Identifier


go to your masterdrive–System-Library–Extensions–
IOPlatformPluginFamily.kext-Contents–Plugins–ACPI_SMC_PlatformPlugin.kext–
Contents–Resources – find the name from step 3 and move it to a
folder that you can find again if needed.



Now reboot and check, if your mac is running better. you can also    check in disk utility the kerneltask before and after youremoved the    file. dont forget to enable your sip now. 
what is about your cpu    temperatur or fan, to high? you can solve this
only by disconnect you    battery and powersupply. Now hold down the
on/off button for min 5    better 10 seconds. Rebuild your batterie
and reboot. Next thing is pr    ram reset, start while holding
cmd+option+p+r, wait until you hear    the loud mac startup sound
and release then the mac start up again.    clear cache by start
while holding shift, log in and reboot.  that    should make a hugh
    difference like before. you can run from time to    time in terminal
    sudo purge   to clear your used ram. cheers**