MuseScore 1.3 Download: Error Opening DLL's

I have tried to download MuseScore 1.3 about four times now, and it is coming up with errors like:

Error opening files for writing:
C:\Program Files\MuseScore\bin\QtCore4.dll
C:\Program Files\MuseScore\bin\QtGui4.dll
C:\Program Files\MuseScore\bin\QtNetwork4.dll
C:\Program Files\MuseScore\bin\QtScript4.dll
C:\Program Files\MuseScore\bin\QtScriptTools4.dll
C:\Program Files\MuseScore\bin\QtSvg4.dll
C:\Program Files\MuseScore\bin\QtWebKit4.dll
C:\Program Files\MuseScore\bin\QtXml4.dll
C:\Program Files\MuseScore\bin\libgcc_s_dw2-1.dll
C:\Program Files\MuseScore\bin\libsndfile-1.dll
C:\Program Files\MuseScore\bin\mingwm10.dll
C:\Program Files\MuseScore\bin\mscore.exe
C:\Program Files\MuseScore\bin\portaudio.dll
C:\Program Files\MuseScore\bin\iconengines\qsvgicon4.dll
...and so on.

Every .dll doesn't seem to want to download, including the program itself.
Has anyone had this problem, or is it just time to upgrade to a new computer? I have Windows XP SP3. Would this be an OS problem?