Windows Firewall

[douglas9401]

When I turned on my computer this morning it was unable to connect to t'internet.
Firefox suggested a check on firewall settings to make sure it was authorised to make connection. Went to control panel, double clicked the firewall icon and got a message saying that it couldn't open due to an unknown problem.
On the off chance there was an invader lurking I ran a full scan with Microsoft Security Essentials taking the best part of seven hours and it came back with ni problems.
If Windows and Firefox don't know, what chance does little old me have?
Computer's a few years old Dell Dimension with Firefox and Windows XP.

Any ideas anybody?

Ta.

[douglas9401]

I should add that, obviously, it's working now and laptops and phones in the house get online with no problem at all.

[Alston]

Seven hours to do a Scan. How big is your Hard Drive and how much of it is full.?

Al.

[douglas9401]

Thanks for taking the time to reply.