I attempted to increase c-drive memory by using a partition tool,earlier i had my system dual boot(window8.1 and ubuntu 15)now after doing the partition using partition tool when i start my computer it shows

GNU GRUB version 2.02^beta2-9ubuntu1

Minimal BASH-like line editing is supported. For the first word, TAB lists possible command completions. Anywhere else TAB lists possible device or file completions.

please help me solve this problem,how can i get both mu windows and ubuntu back