My laptop is extremely slow.  I just reloaded the OS (windows  10) and it  made no difference.  I noticed  something odd in  that  when  I  look in Task manager  on the  Performance  tab, the CPU is only 23% utilized AND the clock speed is ONLY 0.5GHz as shown with the utilization  percentage. The advertised clock rate is 2.16 GHz which does  show  up in the Properties tab as well as in Task  manager  (as part of the header).  It  seems like my CPU  usage is  stuck at 23%.  I have only seen it move down to 22% on occasion and never up.   

As an example, I used the  Detect  This  PC option on the Dell Support website and it took over 10 minutes for it to respond.

IT appears  that my laptop is only running at 0.5GHz.  The slowness  of the pc  would  tend to support such  a slow  speed.  For the  record, the slowness is in everything from opening Windows  Explorer to  browsing any website.  I changed  the  Power Plan to High Performance but  it made no difference.  The  laptop has 4G of  RAM.   Does anyone know why my pc is only utilizing 1/4 of the clock speed?