Hello mstrwnn,
Welcome to the HP Forums!
I understand you would like to lock the touchpad, and sometimes it is slow. Normally you can lock the touchpad by pressing the top-left corner of it three times. To assist you further, I require the following information:
1. The computer's model number. If you require assistance locating this information, please reference this website: Guide to finding your product number
2. The computer's operating system. If you require assistance locating this information, please reference this website to determine your Windows operating system.
3. Does this occur on certain programs, or all programs?
4. Have you installed any new software or drivers on this computer, before the issue appeared?
Additionally, if the slowness issue just began occurring, I would perform a system restore. I want you to bring the computer back to the earliest restore point possible, in an attempt to dodge whatever caused the issue. Here is a document on how to perform a System Restore: System Restore
Thanks for posting on the HP Forums. Have a great day! 
Mario