Network SLOW

Setup
Router - Linksys CISCO E2000
2 Mac Desktop Computers
Windows 7 OS on Parallels Desktop 6
Envision Salon Management Software (Network Version) in Windows

I am having difficulties with this software. The system with the main database installed on it runs seamlessly in parallels. My second computer (our reception system) was supposed to be a "satellite" system. This version of envision accesses the database through the network onto the main (office) computer. Envision on the reception computer locks up when I try and move around in the program. Not sure what else I can do. I've adjusted for best performance on both Windows 7 systems and I have alotted the max memory to both parallels systems. I've tried through Airport and I've connected directly through my router.

Any help or ideas would be a great help!

Thanks