Windows Classic Theme at Startup

Since the other day my theme was switched to the classic theme, and there is no option for the XP theme anymore. I right clicked the desktop, went to Properties, Appearance, Windows and buttons, and the Windows Classic style is the only one availble. This just happened out of random and I've searched google and this forum for answers but there is nothing. I fix the problem by going to Start, Run, services.msc, right clicking Themes, properties, and the service status seems to be stopped. I click start and it works, but it just switches back to classic theme when I reboot. The startup type is Automatic, and the path to executable is C:\WINDOWS\System32\svchost.exe -k netsvcs. Have any of you had a similar problem or know a way to fix this one?