Dell Inspiron 15R 5537: Keyboard issues

​I usually type with both hands. I've had this laptop (Win 8.1) for quite a few weeks.​

​I frequently find some of the keys (mostly on the left side) of the keyboard are not registering, in particular these letters: E, C, D, R, A, S, B and O are problem keys. E and O are the worst ones.​

​The problem gets worse when I type a bit faster than usual.​

​I'm having to either type much slower than usual or proofread extra closely (which I never had to do when using my old laptop before it died) because of missing letters.​

​It's maddening. I've had this problem right at the start with this laptop, and it hasn't improved since.​

​Here's an example of the issue when typing at normal speed with both hands, without any corrections.​

​[unedited] This is just an xample of the issue with the kypresses not registering whn typing with both hands. The letter E gives m the most grief when typin. Somtimes the poblm occurs with other letters. I hav been typing for donkeys years and have rarly ha thi issu thi bad.​

​[corrected version] This is just an example of the issue with the keypresses not registering when typing with both hands. ​​The letter E gives me the most grief when typing.​​ Sometimes the problem occurs with other letters. I have been typing for donkeys years and have rarely had this issue this bad.​

​I've checked the keyboard and there aren't any defects that I can see. No crumbs or dust or whatever. I've checked the keyboard settings in the control panel, and the only settings available are: repeat rate and cursor blink speed. Dell doesn't include proprietary​​ ​​settings for the keyboard.​

​How can I fix this issue? Is the keyboard simply not sensitive enough to detect some of my keypresses?​