C: drive thought to be memory stick

Question

Generic problem (I think)...my PC thinks that my C: drive is a temporary memory drive and a symbol is on my toolbar - a device with a green arrow pointing to the left (like it does if you put a memory stick in).
I think this occurred after i downloaded Adobe R8 and it declared war on my Firefox and my PC became totally unstable. I got rid of Adobe and Firefox. Tried to repair XP and after a LOT of work eventually got IE7 onto my PC and repaired XP with SP3, thanks to Microsoft Knowledge base. Don't Go Bill!
What's the answer, please.