GIF imgs dont open, vid formats needed (full list inside)

i recently got a new computer with WIN7 Home , 32 bits .

These vid formats dont work:

mkv

(one of the mkv files had the phrase "h.264-ac3" in its name, if its important for u)


ogm

rm files

flv

one vid file played with video but didn't play with sound - it was .mpg

one file didnt play well - was .mpeg , had slow downs


AND the following photos didnt open -

GIF images, and by that i mean, those gif image who "move", which are like vids but without sound and the Windows image opener thingy used to open these normally on my other computer (who had Windows XP)
Gif images open usually with the internet explorer (even though its not my default browser) and there they are "played" ok (meaning they are displayed flawlessly)

One image is catagolized by my pc as "File". meaning the part that supposed to say GIF or JPEG says "file". it is a moving image which always asks me how to be opened, NEVER allowing me to tick the "always use this software to open this type of files". it is displayed well on the Internet explorer.

Just in case i will mention that i have IE9.

so my questions are what should i download as codecs, formats, whateverr? sound codecs, and vids, how about the k-lite ? i just dont want to clug my pc with codecs. so if u know what i need to DL to make the pics work on the windowd image displayer tool thingy and make all the vids play well, i will appreciate it.

BTW , i have .nfo files who i remember used to open up well years ago but recently , even though i dont think i need them, they don't open up well. this is the message i get when clicking on them :
"The system information cant open this .nfo file. it might be corrupted or not compatible for this version of the system information"



THANKS IN ADVANCE FOLKS !

VLC media player.will play just about anything

ok where to start, on the nfo files right click and select open with choose select default program then use notepad or word pad, you will have to browse to them and set the default.

gifs wont open with windows 7 you will need a third party software i use faststone image viewer. otherwise selecting a gif will open your browser and the image will show in a page

if you want to play mkv using media player or windows media center then install sharks007 codecs they are generally the forum recommended codecs .shark007 is also a forum member here and the codec support from him is second to none
http://shark007.net/