Need better separation between Mac and Windows

I purchased Windows because I found it was better for running my business since my employees are on Windows computers. I ran Boot Camp for a while but it created too many issues that I won't go into. The only problem I have with Parallels is that it doesn't create - at least to my knowledge - a clear enough separation between the two OS's. For example, I have Microsoft Office for both Mac and Windows and when I download a .csv file while running Windows, it downloads it to the Mac OS Excel instead of the Windows Excel and switches me over automatically. I can't find a setting that allows me to keep things clearly separated. I'd like to be able to use Windows exclusively while I'm using Windows, and vice-versa. Is there a way to do that?

 

Hello @JasonP8 ,
Please follow the steps provided below to Isolate Mac from Windows
1.Shut Down Windows
2.Open virtual machine configuration http://kb.parallels.com/117287
3.Go to Security Tab
4.Enable the option "Isolate Mac from Windows"
Hope it helps
Thanks, Alfena