download problem & file attributes

Hi all, my dad is running xp sp3 with comodo firewall and avast free edition, but when he tries to download anything when using firefox 3.01 he gets an error message saying he cannot access c/doc&set/downloads & he has to either change the file attributes or change location. i/we have tried to do this in ff options to no avail & even tried resetting preferences relating to download directory config in location bar).tried reinstalling ff with older version & updating but it only updates so far. anybody have any ideas?, hope i have given enough info.

tnx in advance

 

tnx for the quick reply davidgp, in reply to ur questions i will get him to try & d/load from MG but the problem seems to be all d/l's, IE wont start for some reason anyway,havent tried the safe mode option yet but will do and he is in admin account & the only person who uses the pc,will post back later with results(have to work till 9pm tho) tnx again.

 

ok have d/l ff4 in safe mode & installed,also d/l malwarebytes & running full scan now,kept getting time out error from MG but have it now will post results of scan later,have to work again,many tnx for your help guys.reason for ff 3.0 was it was the only exe on his pc after uninstalled later version.hopefully this is sorted now.

 

ok still having same probs despite d/l FF4 and doing some cleaning with malwarebytes,i will send some programs on disc to my dad to install & run (he in uk, me ireland) & try & clean more,tnx again for all help will report results when i have them

 

quick update,have installed google chrome & d/l & streaming probs have gone,also upgraded ram & done a little more anti virus and spyware cleaning,i still think there is a problem with windows as uninstaller not working but can live with that