Programs such as Word load very slow

I have had Parallels loaded with my new MacPro for a month. It was working outstanding and then in the last few days everything takes forever to load and then just freezes. Also when I try to open a Word file, it want to "find root files" instead of opening the Open dialog box.
Any suggestions as to what has changed or how? Thanks!

 

When the Windows slows down, check in the Task manager what might be causing this: http://support.microsoft.com/kb/323527

Also, you can try increasing virtual memory for the Windows: http://download.parallels.com/desktop/v4/docs/en/Parallels_Desktop_Users_Guide/22624.htm
The virtual machine has to be stopped if you want to make any changes.

If there is any anti-virus installed try uninstalling it and vice-versa, if there is no anti-virus, check the VM for viruses (i.e. with Parallels Internet Security). Both could be the cause here.