Help please

[Wizz]

am new to the fourm but noticed it was active so mabie use can help me

my problem is my download speed. i have had problems the last 2 days with my broadband speed (Pages take alot longer to load than b4)
i have 2 pc connected via earthnet cable and 1 wireless laptop.
my ISP said my line will be able with 8MB download speed, but test shows 400Kbps-1000Kbps. So i phoned my ISP they sed "Ur line is okay, it must b the pc or software on the pc or mabie the browser"
Ok as i said i have 2 pc connected both have slowed down 1 uses mozilla firefox and other uses internet explorer 8 or watever the latest1 is at time of post. even laptop has slowed.

HELP ME im not used to such slow line after receving months of pretty much perfect internet connection fot the last 6+ months, oh and my package hasnt changed or updated still same as 3 days ago wen problems started. drivin me crazy.

any advice on what i can do?
tahnks in advance