Error on attempt to enter the command

Hello,

Thank you for your prompt response. I tried to type the command
Echo y | reg delete HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableTaskMgr

and repeated that a number of times but I am wgetting an error message " invalid Key parameter " .
Copy and paste is inoperative. Is there a faster way than the manual typing ?
Thank you

Windows XP running on HP laptop.