u727 connection sharing help

[Rebeca_H22]

I have a Sprint Novatel U727 air card. I have had this for a while and used to e able to share the connection between my two computers and a roku. I was having problems with my laptop getting too hot from sitting on for hours and my desktop, a vista wasn't sharing the connection with a router. I decided to get a cradlepoint router. It worked great for the first 5 min. Then I had problems with disconnecting every 5 min. So I returned that and decided to update my air card. I did this big update and ever since then I cannot share the internet at all through the card. I have a new desktop, win7 and when the card is plugged in to the desktop I can connect to the network through a router on my laptop and the roku but can't get the internet. I shared this problem with sprint and the lady tried to sell me a cradlepoint again and told me that I should be able to share the internet connection unless I have the cradlepoint. I think during the big update I did it changed something and now does not allow internet sharing. If there is someone out there who can get through this novel and help me I would love you forever!! p.s. I live in a rural area and can't get any other internet right now:(