new to this sort of thing

"TIME" is the make, it was a sort of well known brand in the UK for a number of years until they went bust, think maybe 5yrs ago, but would have to look that up to be accurate, likely both will be 32bit hardware and Windows, again only knowing the brand and the types of PCs they built.

Did have to look them up and they are back in business under a slightly different name added UK to the Time bit http://www.timecomputers.com/


@kitty63, Could you also give us if possible the model varient of Time PC? should be on the outside of the case, on a sticker or printed on the case.

And how long ago did you buy this PC?

Is this SD card slot a new one you have added, or was it built into the PC, if it was an addition, what is the make and model? when you put in the SD card does Windows make any sound/noise (bing bong or such), do you get and error messages when putting in the card?

If you open Computer Management (Control Panel > Administrative Tools) and then Disk Management and with the SD card plugged in do you see a removable drive?

If you open Device Manager up, (Right click My Computer and choose Properties then the Hardware Tab) and are their any yellow ! marks?

While in Device Manager and again with the SD card plugged in, open the Universal Serial Bus branch up (click the + ) and do you see listed?

 

If the card is an sdhc one, chances are good that your computer simply can not see it.
Most of my computers can't see the newer sdhc cards so I got one of these
http://file.walagata.com/w/perk/MjG/sdholder.jpg
it is the size of a USB thumb drive. The back lifts up, I put the sdhc card in it (I have several 4GB and one 8GB cards) put the device into a USB port on the computer and all my computers now see the card.