My wife has an older version with an older i7 that yours can beat up. As to the 20 minute boot if it is software a restore to factory condition should clear that up.
I take it from your post that you are not into Windows to manually check things out.
About a year ago, I decided to purchase a touchscreen windows 8 laptop. I like speed, so I made sure it had an i7. I bought a Dell Inspiron 15R 5537 for $650, and it was reasonably fast at first, but not i7 fast. I had not intended it for gaming, but keyboard lag was unacceptable for an i7. Upon reading the full specs page, I discovered what a lousy excuse it was for an i7. It is an i74500u, designed for ultrabooks. It is 1.8 GHz, but DUAL CORE! WHAT KIND OF I7 IS DUAL CORE? I set the turbo boost all the way up, and continued on with life. A year later, it is SUPER slow. It sometimes takes 20 minutes to boot up, and even web browsing is torture. Is there any free or cheap way of speeding this up AT ALL??? Or am I simply missing something obvious?