Am i able to get windows again (PLEASE REPLY!) ?

OK so my computer was going really slow and i couldnt do anything and i had to switch to unbuntu..........my computer is a windows computer and we switched to ubuntu?!?!?! Now i cant download imvu, sims 3, zoo tycoon ANYTHING i cant even watch a stupid movie! Now am i able to go back to windows?? PLEASE REPLY!