I am new here and not sure where to put this

1- i am on a dell optiplex100 256 meg ram xp

problems

1 every link i use on your site throws back this error error trying to read source source file is corrupted -advanced windows care and the new system care - driver scan usaes that one and adds askes for fresh copy or it is pasword protected and i have wrong password-

i have tried fl sites andtexas siters with same problem occuring

also have similar download issues on other sites except yahoo - it lets it through
those are i/o erros while reading source file- bad installation media or source file corrupted was even giving this on microsoft site

i have ran scandisk clear- ran antvirus kaspersky 7.0- it is clear- it gave static about downlaoding updates through program but was able to go to site and due it manuelly
2 extractors throw the same erros as well
3 thouroughly- dumped programs and files- - diskclean up sever times
4 went in and dumped cookies folder manuelly andtif and temp files and prefetch

still having same issue in ie and firefox as well
chkdsk came back clean- defragged

it is letting windows update through now but that is all- tried to reinstall my yahoo im and it said it installed but where? no programs in lists or add remove either

weird

what next?

oh 10 gig hardrive have 2 gigs open