downloaded ccleaner pro plus and having issues

[joel m]

i just bought and downloaded ccleaner pro plus, with defraggler, etc etc after downloading , i ran the defraggler, but before it could finish running, it made my computer, reboot itself!! then i got a error saying alert had drive or disk not found, press f1 or f2 or f5, i pressed f2 and it put up a screen showing something about my dell computer, x out of that, then got no vga signal , turned monitor off and on, and it finally reboots up,  but then wont go into sleep mode, if you walk away it just shuts down tries to rebott and you get the alert message all over again and hit f2 and so on and get it back up and running!! i need help!!!!

[nukecad]

That does not sound like something that Defraggler would do.

Noting the date and the time of your post I suspect that whilst Defraggler was running you have had an automatic restart as part of Microsofts Patch Tuesday updates.
The Patch Tuesday updates will have started being sent out a few hours ago.
https://www.bleepingcomputer.com/news/microsoft/microsoft-april-2020-patch-tuesday-fixes-4-zero-days-15-critical-flaws/

A Windows Update restarting the computer without asking you first shouldn't happen, but we know that it can and has done in the past.
I haven't seen any other reports of that behaviour with this one yet, but it's only been a couple of hours.

In Windows go to Settings>Update & Security>Windows Update>View Update History and check if you have updates from a few hours ago that have not installed sucessfully.

If you have failed updates (In particular KB4549951) then go back a page and click on 'Check for Updates' to try and reinstall the failed update.

(I'm just going to manually do my PT updates now so may be missing for a while).

[nukecad]

This is what I wanted to show about the updates:

Note two things there-

The second line "Your device will restart outside of active hours."
Then at the bottom of that screenshot "Change active hours".

If an automatic update happens outside of the Active Hours that you have set then it may just restart your PC without any warning.
(It should give a warning, but you may miss it).

See more about Active Hours: https://support.microsoft.com/en-gb/help/4027636
Also see "How do I make sure my device restarts to install updates at a convinent time" : https://support.microsoft.com/en-gb/help/12373/windows-update-faq
 

[nukecad]

Just to add that my suspicion about the Updates may be wrong, and it may just be a coincidence of timing.

It is an outside chance that your HD was on it's way out anyway and running a disc intensive operation, such as defragging, has caused it to give up the ghost.

It doesn't happen often but drives do break or wear out, just like any other equipment.
https://www.howtogeek.com/341268/what-to-do-when-your-hard-drive-fails/

If you are still getting the reboot problem with your Dell then I would use F5 to run the automatic diagnostics.
(F2 runs the setup utility, you would need to go through that yourself step by step, let the automatics do it if they can).
But it may be that the disc has simply stopped working and will need to be replaced.