I installed SC on my old comp cuhz my other one was under repair.  I put a key(Not the one from the box) and my name.. Laoded SC:original and you know how you have to clikc OK to download the knew ver. well i did that and a pop up came up saying :  " Battle.Net was unable to properly identify you application program.  Please reinstall from the CD and reconnect to Battle.Net. "
I reinstalled like 5 times and it still got that.. any help?

Reinstall again, only this time download and install the patch manually.

Odd...That just recently happen to my friend...

If Nevar's suggestion doesn't work, scan your computer for viruses. Viruses infect programs, which modify the executable, which would cause the check to fail.