Im pretty sure this is not vanilla, but I have a trapdoor near cauis cosades house called 'unknown cellar' with a 100 lock.

Im not sure where it came from, the only mods I have are

MCP, GCD, Ald Vendras, DB attack delay, ranger robe, all silt strider destinations.

I cant use the console to open it either.

Walk up to it, open the console, select the door and type in 'ori.' This will tell you what mod it's from.

I cant get the console up at all.. my vista laptop wont allow it.

Why not fix this problem?
http://www.gamesas.com/index.php?/topic/781497-vistawindows-7-problems/page__p__11389133#entry11389133 Or just use MGE to make a macro.

tried it, console still wont open. Nvm, I'll just leave the mystery till im able to open it.

Try unchecking each mod and restarting until you find which one it is. Your modlist isn't so long that it would be too much trouble.

EDIT: I can tell you right now it isn't GCD or MCP and DB delay wouldn't add anything to the game world, nor does all silt strider ports..

i thought it might be Ald Vendras i used it once and never made it that far in to it's quests but it's the first mod i though of with out seeing your list

Try this http://en.wikipedia.org/wiki/Netbook#Gallery and enlarge the keyboard pictures there is.

When you find a keyboard/layout that are close to your laptop just look for the "Esc" key (under or next) to find this " ~ " or " § " key (tilde key for the console).
Since you have a laptop you may even need to use two or three keys (Alt / Ctrl / Shift) all together simultaneously plus the tilde key to bring up the console.