You can't open most texture packs directly in Minecraft (yet). Please follow these steps to install a texture pack.
First of all open the MC launcher, click 'options' then click 'force update'. Now proceed to login like you normally would. Exit the game. There are multiple ways to install a texture pack. You can use a handy tool like HDpatcher to easiliy use texture packs. Here is the link to HDpatcher: http://www.minecraftdl.com/mcpatcher-hd-fix-texture/ Scroll down and click "Download MCPatcher HD Fix for Minecraft 1.3.2 Now" After 5 seconds you can skip the ad.fly ads and continue to download it from mediafire.
After you have done that simply open the MCpatcher, click the + and add your texture pack by double-clicking the zip file. Then click 'ok' twice and lastly click 'patch'. This should work. It might be wise to allocate more memory if you get a black screen on startup or low FPS.