RSA keys less than 1024 will be blocked in August.

In August Microsoft will be pushing out an update for all of their supported Operating Systems. This includes Windows XP, Vista, 7, Server 2003, 2003 R2, Server 2008, and 2008 R2. This update will block the use of cryptographic keys that are less than 1024 bits. This must happen because with the evolution of technology it is becoming easier to crack weaker keys with less and less time.

• Error messages when browsing to web sites that have SSL certificates with keys that are less than 1024 bits
• Problems enrolling for certificates when a certificate request attempts to utilize a key that is less than 1024 bits
• Creating or consuming email (S/MIME) messages that utilize less than 1024 bit keys for signatures or encryption
• Installing Active X controls that were signed with less than 1024 bit signatures
• Installing applications that were signed with less than 1024 bit signatures (unless they were signed prior to January 1, 2010, which will not be blocked by default).

You should determine whether or not you are currently using keys less than 1024 bit to prepare for this update. If your are using keys less than 1024 than you should plan to update your keys to 1024 bit or above. You can get help with this following this link (here)