Hi buttejimmer ... and welcome to the forums ...
Any luck with the Start Menu issue yet? If not ....
Many Dells come with a year of on-site support. If yours is one of those, you can have an actual human being come out and fix it. Note that the onsite is often for the business models.
If the trouble only surfaced in the last few days, you can try using System Restore to resolve the issue (if System Restore is turned on, that is). You'd choose a "restore point" from before the Start Menu started playing hide-and-go-seek.
System Restore in Windows 10
1)
Right-click the
Windows Start Menu icon
2) Select
System
3) Select
System Protection (a blue link in the upper left-hand corner)
4) Select
System Restore
5)
Choose a restore point from
before the current trouble started.
If this doesn't work, you might want to run the built-in Dell Diagnostics for your computer, to make sure that a faulty part isn't causing trouble. Instructions are available in the Dell user guide, as well as online on their support site for your model. They are very easy to start, you usually just press a special "function key" as system power-on, to choose the Diagnostics from a menu. On many models, this is the F12 key. The best instructions will likely be those in your system's manual, but here are some generic instructions from the Dell support website:
What Dell diagnostic tools can I use to fix hardware problems? | Dell US
If you have any hardware issues, let Dell know right away, so they can fix things while under warranty (free).
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If the hardware proves stable & healthy, and you haven't set the computer up much, you can always use the built-in Dell tools for system recovery, or the built-in tools for system recovery that come with Windows 10. The Windows 10 built-in tool that you can try is called a System Reset (you would use the option that would "keep files" [it saves any personal files you've added]).... You would have to reinstall any programs added since the computer came home from the store (or the UPS truck)....
Let us know if you have questions.