Windows 7 - error 1316 for install blackberry software

Dear all,
i am not able to install blackberry desktop software in any condition.
Firstly here is my computer config:
Windows 7 ultimate (upgraded from Vista Business) 32bit
service pack 1
only 1 user profile with all admin privileges.

I was using/syncing with desktop manger v5.0.1 without any problem over 2year. I changed my phone and new phone required latest version of this desktop software.
I uninstalled previous version as blackberry advice in their support website.
after that run 2 different registry fix/cleaner software to check and clean leftover regs.
I downloaded from blackberry web site latest v6.1version.
when i run the installer installation starts but afterwhile it comes error 1316(a network error occured while attempting to read from the file C:\windows\installer\blackberry desktop software.msi) and installation stops and rolling back process.
after that i read all the forums related 1316 error but as now no any solutions. I can't install this software to mycomputer.
I checked almost every forums related with this error in BlackBerry supports but neither resolutions worked so far.
every time before I try installation, i am deleting all the files, running registry fix editor which is created from previous attempt.
even i create another user profile with admin rights but also same result.
also i tried to extract .exe file which downloaded from server and copy&paste "desktop software.msi file inside of the C:\windows\installer folder but in this case i had error 1311 "source file not found:C:\ windows\installer\data1.cab. Verify that the file exist and that you can access it."
even i places as well data1.cab file from extracted install folder and placed as well C:\windows\installer\ folder, but this time i got error 1334 which says "the file "a_picture_folder_is_not_reco' cannot be installed because fiel cannot be found in cabinet file "data1.cab" this could indicate a network error, an error reading from CD ROM or a problem with this package.

this package is direct installment from blackberry web site and it is 1 time solid and consistent download, so i don't think it can be something wrong in the installment package.

so far i also tried to create another user account with admin priviliges and install it there but no result.
installed microsoft fixit but no result.
performed a clean booth, disabled all start up and services (excluding Microsoft) and tried installation but again no result.
as i explained above during these mad loop, i did countless registry cleaning/fixing with 3 different software.

i am almost out of option. i am reading some manual registry editing posts but i am not sure how should i follow. i will be really appreciated if someone can help me about to fix this problem.

many thanks in advance.
Burak