Epicor 9 Client Installation Error

I got the below error during Epicor 9 client installation.

"The Client installation requires 1000mb of free disk space but selected drive has 1000mb. Please select another location for installation" 
I checked the disk space and I found there are 40 GB free so whats wrong?

 To solve this issue you have to check the prerequisites installation:

1- dotNet framework 3.5
2- Microsoft WSE 3.0 Runtime 

After installing these prerequisites you will be able to install Epicor 9 Client.