Existing users, 
After upgrading to Parallels 5 I was unable to run the virtual machine I had been running flawlessly since first installing Parallels more than a year ago.
Geting support is IMPOSSIBLE! You need a 10-digit support code to do anything - and the support codes that are SUPPOSED to be available on your account info page are NOT.
On-line help has NOTHING on version 5 except for saying that all version 5 owners are entitled to 18 months of free support (that you can't get without the support code that' NOT where they say it will be!)
The "Getting Started" guide says that Parallels will need to update your VM (and that it will take a while), but the program started right up, and immediately went into a Blue-Screen-Of-Death/reboot loop...
Parallels Desktop
Run Windows simultaneously with OS X.
Version: 5.0
v4 worked great - v5 won't even boot
Feedback Type: Review
Contributed by: Linefeed Wednesday, November 04 2009 @ 09:09 AM PST
Product Platform: MacOSX
Used Product For: Less than a month
Recommend Product: NO
Overall Rating:
Ease of Use:
Support:
Features:
Quality / Stability:
Price:
Comments
v4 worked great - v5 won't even boot - DRNash--2008
The posted solution worked for me.Thursday, November 05 2009 @ 01:31 AM PST
v4 worked great - v5 won't even boot - klpete
I'm getting the same thing. Blue screen of death. The first time I've ever gotten this in Parallels!Wednesday, November 04 2009 @ 11:52 AM PST
v4 worked great - v5 won't even boot - krauses
From the Parallels forum. It worked in my case, but others reported that switching back to more than one core messed things up again. FWYW:Please do the following:
1. Shut down your virtual machine if it is started now.
2. Set virtual machine CPU number to 1 in VM configuration. To do this, open Virtual Machine menu->Configure... and set "1" in "Processors" drop-down.
3. Start the virtual machine. This time it will boot normally.
4. Login and wait until Parallels Tools are installed.
5. After Parallels Tools are installed, it is safe to return the previous CPU amount.
Wednesday, November 04 2009 @ 01:55 PM PST
v4 worked great - v5 won't even boot - Alan Fink
There is a support article for this install issue. Goto the configuration screen and change number of processors to 1. Start VM and let it complete tools installation. Reboot and change back to more than 1 processor if you wish. Worked for me.Thursday, November 05 2009 @ 05:15 AM PST
v4 worked great - v5 won't even boot - DRNash--2008
Same problem here - I hope a timemachine restore will be effective...Reply to This
Wednesday, November 04 2009 @ 10:21 AM PST