Cab files changing format

Sorry if i'm in wrong area but this is my very first post! My problem is when I download a .cab fiile or zipped file with cab in it when I try and install it the cab file changes from a cab icon to a windows icon and will not let me install. Some programs have been installes fine and some wont install no matter where i get the software and i'm getting frustrated. Im using a touch pro 2 pretty much barebones with just a few addons like reg editor. Please help
PS: Also when I open the cab file to install it says the file cannot be opened,either it is not signed with a trusted certificate or one of its components cannot be found, try reinstalling or restoring this file... Ive done this with diff files and still get same anooying message.
PSS: I just downloaded personalizer and mortscript from ppcg and it did same thing..also it dont matter if i dl from desktop or phone same result,i used to be able to install cabs with no problem..please help.

[creedo]

Can you point us to a sample cab file that's giving you trouble? Maybe they're not really cab files. Or they're windows cabs and not windows mobile cabs. Sometimes you'll see a link to a .cab file in a web page, but when you go to save it, you end up with a file that is actually an HTML file, not the cab file.

First, make sure any cabs you have are unzipped before installing. In later windows OSes you can just treat a zip file like a folder, you click on it and see what's inside. But it's not truly unzipped yet. So you don't want to try to run the cab yet. Unzip it somewhere and then go there and run the cab from the new location.

Also make sure you are using a file explorer that can see the extension of your files, so you can be sure that the .cabs are really cabs. Total commander is a good one.

[firetiger]

Download sdkcerts.cab. Search for it in ppcgeeks...