Is this happening in all programs or just a specific one? If it is in all things, try this...
NOTE: If you need to type in a password to even get into Windows to do the following, make sure you attached an external keyboard first, to get past the password. Then disconnect the external keyboard and try the following...
1. Uninstall the keyboard driver.
2. Reboot the computer (without reinstalling the driver).
3. When it restarts, it should reinstall the driver on its own.
If this doesn't work, you may wish to try connecting an external keyboard and see if it works fine. If it does, then it could be the keys themselves that are the issue.
You may also want to try updating the Synaptics Driver if the above doesn't help.
If it is only happening in one program, try restarting the laptop and see if that resolves it. If it does not, you may want to do some good deep virus and also malware checks on the computer. And should that turn up nothing, then I would consider uninstalling and then reinstalling (after a reboot) the program that is giving you problems.