umm.... if u r downloading using a download manager (such as flashget) try not to split the file (when you download it asks you to how many parts do you want to split it to)
or use the normal download
and if it still didn't work ... then I'm not sure what's the problem
executing problems occurs usually when either the file is damaged or if your pc got some problems with executing it
and as that if you re installed windows .. then I dunno
sorry >_<

u guys are confusing
and sorry that I couldn't help you ... but can someone provide a screen shot ?