When I press the open button, it doesn't open.. what's the problem?

Don't know, but you can open it this way:
Open My Computer
Right click on the CD drive and select Eject from the popup menu

Yeah try JB's answer first. If that doesn't work, then as a last-ditch thing try this:

On the front of your CD-ROM Drive, there should be a small hole. Find something long and thin (preferably non-metallic) and slowly press it into that hole. That's the manual release for your CD Tray, if nothing else works!

I say "Non-metallic", but people normally use un-bent paperclips! You may have to press quite hard as you're actually forcing all the cogs to turn that open the tray!

Oh, and once you have your CD out... does it solve your problem? Will it open and close now?

I tried ejecting it on right click menu but "my computer is not responding"..

I can't find that hole..

i can't find that hole..

If it's on a tower PC, you may need to remove the drive from the casing to find it!