DMG files will not mount, tried everything!

[happynoodlegirl]

im downloading the dmg files (mac dvd player and vlc, because somebody deleted my dvd app and i dont have the original disks) with a windows pc which is apparently fine (ive try to transfer with both memory stick and cdr) , and ive used disk utility to repair the hd and to repair permissions and still nothing!
any advice will be appreciated, cheers!

 

[eyefoniac]

Sometimes the file won't completely download and it will appear as a complete .dmg but actually won't be. Try re-downloading the file to make sure you have the complete file. If it is incomplete it will fail to open the .dmg.

 

[happynoodlegirl]

Ive now got dmg files to mount, they were somehow becoming corrupt when burnt to cd....however!!!!
everything i install on to the mac doesnt work, installation has been followed correctly and they are present and correct in the apps folder but they just ****ing bounce up and down when i try to open them or when a program trys to launch them, any idea ?