With too many programs opened at once my MacBook Pro froze while Parallels was running and I had to force restart. Now, whenever I open Parallels, the installation screen appears, just like there is no Windows installed at all. I don't want to loose all my data by having to reinstall Windows. Parallels 3.0 build 5626. Any help would be appreciated.
Check if you still have the hard disk image (.hdd) on the Mac side. By default in /Users/<username>/Document/Parallels/<VM_name> or /Users/<username>/Library/Parallels/<VM_name>. If it is - try creating a new virtual machine (custom mode) using the existing hard disk image.