Problems with GARMIN nuvi 2555LM???

My son gave us this GARMIN GPS about 2 years ago. In NOV of 2013 was the first time we used it to go from Yukon, OK to Chicago and return. It worked beautifully both ways. Then I noticed on my computer that there were some upgrades that were ready to install. I plugged in the GPS and successfully down loaded the upgrades. Then in August of 2014 we went to Iowa and the VOICE DIRECTIONS did not work this time! We tried what it said to get the voice to work again, but the icon that we were supposed to touch was not on there? Now today Dec. 29, 2014 I noticed there were new upgrades available for it. I thought that maybe if I downloaded them the voice portion would again work! When I plugged in the GPS to the computer the GARMIN screen lit up and was talking to the computer. Right after I hit the UPGRADE button on the computer a message came up that said "CONNECT DEVICE TO COMPUTER"!!! At this time the GPS screen showed a dim GARMIN on it with a dim display with a GPS and a connector to a computer! The GARMIN was connected to the computer all the time! Now the dim display stays on the GPS and I cannot get anything else to get it to disappear. I even took it out to the vehicle and plugged it in and it did nothing. Does anyone else have any ideas what is happening, or did it pick up a few bugs in both downloading processes? Thanks for all replies. Gary