It was caused by a registry cleaner that I was using at the time.I don't remember which one though.This is the solution that worked for me.

a. Click Start, click Run, type cmd to open a command prompt. Type the
following commands:
net stop helpsvc
cd /d C:\Windows\pchealth\helpctr
rd packagestore /s /q
cd binaries
start /w helpsvc /svchost netsvcs /regserver /install
b. Run Taskmgr.exe to launch Task Manager. If any of the following
processes are running, stop them:
helpsvc.exe
helphost.exe
helpctr.exe
c. At the command prompt, type: net start helpsvc