The C drive should not be removable because it is always the boot drive. Sometimes Windows will show a primary SATA drive as removable, but this is a bug - its not a "feature". At any rate, the proper C drive should never be empty!
You have some serious issues there. Please post a picture of the My Computer window. Bring it up and press Alt-Print Screen (PrScr). Open Paint and click Edit > Paste. Save as a JPG and upload it. If you can, do the same with Disk Management. Start > Run > Diskmgmt.msc > OK. Eliminate the scrollbar by expanding vertically until all drives are visible. Capture that too and upload.