How to check installed software's version?

Flash installed, but still not working. Also Quicktime error?

• I just installed the latest version of flash. When I go on youtube to check out videos, it won't load. Same with other sites like justin.tv. Also re-installed quicktime, but I get this error entitled "QuickTime Unavailable" and the message says "The QuickTime plug-in requires the QuickTime system extension version 5 or later." And then it links me to the download site for QuickTime. Any help on both problems would be appreciated.

• Answer:

  this is not a big issue, its very easy to solve if you have some know how of system registry because some of your files are disassociated from registry values that is why the problem occur. this not only happens with flash but many other programs can disassociate, for this you have to clean windows registry if you can otherwise use some kind of registry repairer software like reginout.