please google take ownership [For Win7],
install it, and go to the Program File or Program File X86, find the Baidu's file,
right click on it and choose Take Ownership, Work Done, then try to delete the baidu's folder.
IF above way still cant settle, i guess mostly is Virus,
Go to Dr.Web Official download a program which named "Dr.Web Cure It!"
Use it to scan whole your computer and KILL it.