[Windows Vista]
Goto: C:\Users\[user]\AppData\Roaming\2K Sports\NBA 2K10\Saves
you will see the following file

• Config.cfg
• Game Records.rec
• Game SLiders.sld
• NBA Today.lsf
• Player Progression.ppf
• Roster.ros
• Settings.stg
• [user].usr

Back up files before you delete it!

DELETE it all, then load back your nba2k10.

note: If there are any other files on this folder delete it also.