How to deal with windows partition manage on a computer?

I installed Windows 7 on a partition on my C Drive, and I would like to delete it. I've tried going to Manage, and then Disk Partition Manage, but whenever I try to delete it it says that, 'the partition has page files or boot files in it'. I'm not sure what that mean, so I really need to get rid of this partition. 

I don’t know what to do， so search google for "delet partition", while i find Tenorshare Partition Manager software can help me to delete windows 7 on a partition, i decided to try it.

Tenorshare Partition Manager is a partition manager that offers superb partitioning features, like extending, shrinking, formatting, creating, deleting and copying partitions. A task-oriented wizard guides you through step-by-step processes. You can complete the function with nothing more than a few clicks of your mouse. Here are some steps to delete a partition with Tenorshare Partition Manager

Step 1: Downloaded Tenorshare Partition Manager from it's offical webside, and used in laptop.

Step 2: You can view all the partitions, along with size, partition type, file system and etc. Select the one you need to delete, and choose "Delete".

Step 3: A windows appears to remind you whether you want to delete the partition. Click "Yes" to confirm.

Step 4: Hit "Apply" in the top menu to apply the operation. 

Thank for these steps, it help me delete windows partition manage quickly. I hope   these methods can help you well if you also met the same trouble with you.