Hmmm. When asked if you're rooted, you replied no. A few posts later, you said you rooted via Toast's method, and using Evo recovery. Having a recovery image flashed and unlocked implies that your phone is rooted. It is important to know the status of your phone, so:
a) Is your phone rooted?
b) Is your phone stock?
One of these answers is yes, and the other one has to be no. If you're not rooted (though I think you are), you don't need any help, just take the phone back. If you are rooted, we can help you get back to stock. But you need to know and understand the difference, in order to not make an avoidable mistake.
Also, is the central issue that your computer won't recognize the phone in any way, or that neither the phone nor the PC recognizes your SD card?