My SD card reader on my Sony Vaio will not read the card...it seems to know its in the slot, but won't read any data and says 'insert the SD card' if I go to computer and try to read it. Any thoughts?

Take a can of air and blow some into the slot to make sure dust or dirt isn't getting the way of that reader trying to read the sd cards.

If you still get the same message try another SD card in that reader or try to see if another computer will read your SD card, if another computer will read the SD card and the slot still won't recognize the sd cards properly, then you know at that point the reader is bad. If the reader is bad, thats integrated into the motherboard so the motherboard would need to be replaced.

Do you only have one sd card slot? Also try and insert and then press the drive c d e f whatever that the sd card is in. Right click that and the card should be recognized. Insert a couple of times if it doesn't then try to format which would erase all data and you should be good to go.