Click on the Home tab on the tool ribbon. Click Set Path. Look for that folder in the list. If you see it, remove it.
If that doesn't solve it, then
>> edit startup.m
If the file is empty, just exit. If it's not empty, look for a call to cd to that folder. If you see it, delete that line and save the file and restart MATLAB to test the fix.
If that still doesn't work, try
If that still doesn't work, call tech support for fast and free technical support. Ask for Tech Support, then Installation.