Need help repairing windows 7?

windows 7 64 bit. Acer aspire. Computer goes directly to system start up repair regardless of how i boot. Does nothing. Tried using system recover disc but in the erecovery management tool i cannot click on either complete system restore to factory default or restore and retain user data. Says tool failed to run.The recovery disc was made when the computer was first purchased. Downside is the computer is not mine so the owner made no restore points or system images. Command prompt I am unsure how to use but when i do open it i get X:\windows\system32> If anyone has any advice or solutions it would be greatly appreciated. Thanks.