Transfer from: http://blog.csdn.net/luozhuang/article/details/8016558
VC# 2010 Express: PQT8W-68YB2-MPY6C-9JV9X-42WJV
VC++ 2010 Express: 6VPJ7-H3CXH-HBTPT-X4T74-3YVY7
VWD 2010 Express: CY8XP-83P66-WCF9D-G3P42-K2VG3
VB.NET 2010 Express: 2KQT8-HV27P-GTTV9-2WBVV-M7X96
Step 1 Copy the 14-character registration key from above.
Step 2 Select "Register Product..." from the "Help" menu of Visual C++ 2010 Express Edition.
Step 3 Paste the registration key into the "Product Registration" dialog box, and then click the "Complete Registration" button