OS X V10.7 Lion :: Can't Open Almost Any App On My IMac

I can't open almost any app on my iMac (OSX Lion 10.7.4). Every time I attempt to do so, the affected app "unexpedtely quits", showing a window (sort of expanded dialog box) with the log history, wich form a complete report wich is said to be sent to Apple. Despite that this window has a "restart" button, I haven't been able to go any further from this point, as it repeats the process again and again, impeding me to use the affected app.

This has get to a critical point, as it is afecting apps like iTunes (especifically when I turn to the iTunes Store from within te app), MacApp Store, Software Updates (I can't update anything, given this problem) and many other apps, including Aperture 3, Fusion 4, integrated Dictionary and Wikipedia, as I've been able to verify.

Info:iMac, Mac OS X (10.7.4), Intel Core2Duo, 24', 4GbRAM, 500Gb