That happened to me.

Try using JavaRa,its a program that fix java issue's

when u download it(u can download it here)it must open a .zip file,open the one called "JavaRa.exe" then pick the language,Then do this :-
Additional Tasks>Check all>Go

after that it will say this :-

Finished searching.

when u press ok it will say this :-

Found and removed: SOFTWARE\Classes\CLSID\{DBC80044-A445-435b-BC74-9C25C1C588A9}

That means it got the error and deleted it,now u can run minecraft,if it didnt work i will give u other ways





Other step :-
Windows XP:-

make sure you are running the Java JDK (Java development Kit)

Open notepad and copy this:-

java -Xms650m -jar "CDocuments and Settings\Username\Desktop\minecraft.exe

U MUST EDIT THE "Username" TO UR COMPUTER USER NAME.example :-

java -Xms650m -jar "CDocuments and Settings\Dell-pc\Desktop\minecraft.exe


Save it as Minecraft.bat

Windows Vista/7:-

make sure you are running the Java JDK (Java development Kit)

Open notepad and copy this:-

java -Xms650m -jar "C:/Users/Username/desktop/minecraft.exe

U MUST EDIT THE "Username" TO UR COMPUTER USER NAME.example :-

java -Xms650m -jar "C:/Users/Dell-pc/desktop/minecraft.exe

Save it as
Minecraft.bat