extending/boosting my dsl wireless signal - Verizon DLS D-Link DSL-2750B

[#1]

I am experiencing some issues receiving a strong enough wireless signal, especially on our laptops, on our first floor from my Verizon DSL D-Link DSL 2750B router, which is located on the 2nd floor.  Our laptops are corporate, so we are no even permitted to connect a usb wireless dongle.  I have positioned the router in the most effective location for wireless transmission, but because some of our tech usage downstairs is pretty far from the router, we often get only 1 or 2 bars downstairs - if that..

I have been reading many of the posts and answers in this forum about this issue, and I'm more confused now about which is the best solution for me.  How do range extenders, range repeaters, range boosters and Access Points differ; and what is the best resolution that is cost effective (hopefully not more than $100)?

Many thanks!

[#2]

It's best to move the router downstairs to the first floor. Just my general advice to solve this if at all possible.

[#3]

If i do that i won't have a strong enough signal on the 2nd floor where my office is located. We have two offices - one for me on the 2nd floor and one for my husband on the 1st. Both r too smallfor both of us. Also, we use rokus on each floor and need access to our phone and tablet wifis throughout the house. Having access to wifi in only 1 location just isn't working.