Error: -1603 Fatal error during installation

Two days i upgraded my very well running Windows XP running system to Vista Enterprises edition without removing XP (Migrated). The process went fine without any problem but when i try uninstall the incompatible softwares which worked fine in XP but not in Vista, i get the following error messages:

"Error 1316.A network error occured while attempting to read from the file C:\WINDOWS\Installer\neoDVDplus5.msi

Error: -1603 Fatal error during installation. Consult Windows Installer Help (Msi.chm) or MSDN for more info."

As the error says about msi.chm file, i tried searching it every where on my system but dint found it anywhere. Can anyone please provide me some help getting rid of this errors? Thanks for all your helps.

it is due to RAM Problem but before you do anything with ram better checkout the following article: 'Need to Know: error during installation of windows xp professional?' (http://tinyurl.com/2at3jw)