Hello and thank you for choosing just answer.
A problem that you have described, could be any number of things. Really really hard to figure out.
Although, I would start with VIRUS scans, ROOTKIT scans, and MALWARE scans.
Using a combination of different tools to accomplish this.
Do you have Windows Defender updated?
Do you have MalwareBytes installed to check for malware?
you can put the Start Bar back....im 99.99999% sure it has nothing to do with it.
How old is the laptop? Do you visits websites, that might be considered nefarious?
Did you ever open emails with attachments from folks you don't know?
Also....when you say it FREEZES, what d you mean exactly?
Does it just hang for a second or 2, and then go bck to normal?
Or does it freeze up, and the only thing you can do is power it off, using the power button?