Msi u100 plus wifi problem

[acolis]

I recently got a MSI u100 Plus from a friend of mine to format it.

 

I installed windows 7 32bit on it and when I get to the point of downloading programs I encountered a big problem.

 

Sometimes when I download some program(No matter what it is, skype, aimp, speccy etc..)  the download finishes, but when I open the file it gives me errors (like bad hashchecks or something like that)

 

When I use the wired connection it works perfectly.

 

I tried to uninstall the drivers and reinstall them again - no luck.

 

How can I check what is the problem, or if you have encountered it, how can I fix it.

 

Meanwhile installing win XP on the machine to see if it some sort of a problem with atom and win 7.

 

Thank you foir your help