Where to buy Notebook Accessories in Dowtown MSK ? (Moscow)

Hello
PC Hardware :)

Yes i can read Yellowpages :) but i dont want to waste too much time trying out :)
and moving around.

I am for work in Moscow and wonder if somone can advice me a good Computer Store (in Sankt Petersburg i would go to KEY) close to the Pushkin Museum or (Kremlin) to buy Additional Memory for my Sony Vaio ... I need to run a new soft and i have to upgrade it.

Any recommendations ?

regards
MM