Can not run compressor - although no snapshots made

I tried to run Parallels Compressor this morning but receive a message that Compressor can not compress the virtual harddisc. I'm asked to check if there are Virtual Machine Snapshots made which would have to be deleted before Compressor can run.

I checked with Snapshot Mager and found that there are NO Virtual Machine Snapshops on my machine.

What can I do?

Related to this: my Virtual HD is NOT set in sxpansion mode (variable size) but has a fixed size. Parallels user guide does not mention anywhere that Compressor will only work on HDs in expansion mode, so I guessed that I can run Compressor on my fixed size HD as well to do some internal cleaning and get the VM running a bit faster again.

 

Backup VM as in Parallels Desktop for Mac user guide from http://www.parallels.com/en/download/file/doc/Parallels_Desktop_for_Mac_User_Guide.pdf page 243
Use Parallels Image tool and convert to expanding
use Compact from Hard Disk 1 - Advanced first, then start VM and run Compressor

 

I don't want to switch to expanding disk mode (or is there a reason why I should?) - I only want to use compressor to do some clean-up, defragment the HD and remove unnecessary files because my VM became SOOOO slow after about 1.5 years of use and I was hoping Compressor can help here. How do I run Compressor on a non-expanding HD? (note: Parallels user manual does not say it only works on expanding disks, as e.g. Compacting does).

 

You can use Compressor, but it is for additional space on disk not for performance
Compressor, uses NTFS compression, and you can lose more in performance.
Here are tips:
1. Set memory for Virtual Machine to less than 1 GB
2. Perform Mac and Windows (15% of disk should be free) side disk defragmentation http://www.xvsxp.com/system/system_tools_defrag.php
3. Set Adjust memory limit from Auto to Manual at Parallels Desktop -Preferences-Memory, and set limit a bit more higher than VM memory
4. Disable Themes in Windows XP serives.msc stop Themes service
5. If you are running in Coherence, try to switch to Single Window, or lower Mac resolution
6. Some antivirus software can load CPU when Heuristic Prediction is set, or Tamper protection (Symantec, MacAffey), adjust settings to risk you are supposed, high security settings is not always good idea, as it can also affect software running
7. Run msconfig , and disable unneeded startup items
See http://www.netsquirrel.com/msconfig/msconfig_xp.html
8. Make sure that no VNC,or remote desktop connection is established to Mac, this can slowdown Parallels Desktop