Can't Record Glitch

[mainvet]

The same thing happened last summer... now it has happened again. My DAW says it is working right but I can not record. last year I had to restore a saved previous version of my whole computer system to get the recording function to work. I have recorded hundreds of hours and several new song since then and I don't want to lose all this hard work. Since this catastrophic event happened last summer, I have not downloaded any the Reaper updates ( because this is what seemed to cause it last year). Well inadvertently I downloaded the latest Reaper update and it happened again ....I couldn't record again... here is what it looks like... I arm a track and instead of the nice yellow strips pulsating up and down.. I get a dull red color non-pulsating strip for the track.. the "record" function also works but nothing is going through... The Shure USB connected mic is working fine... so what happened. I have tried re-downloading the Reaper version that I had last summer but it still does not record. I asked a computer service and they told me that it is either "usage or hardware connectivity or damage". I know the Shure mice is working, I believe the Reaper program is working. Is there a usage issue... there are so many option that I am afraid I have check or un-check something that interferes with live recording. Or... is it some where in the computer that I am not connecting correctly. - I have checked the computer sound system and it recognizes the Shure speakers and Shure mic and software and Reaper is listing them in the program audio options ( under preferences). When I don't plug in the Shure mic, the Realtech speakers and mic for the computer are listed in option-preferences-Audio device b ut they don't record either. Can anyone help... I am so depressed over this I ready to can the whole system and start over with a new DAW even though I would lose so much.