Windows Update or Any Installs from MS Site

I am trying to update my windows via Windows Update and get the following
error:
"Error(s) found:
Code 80244019 Windows Update encountered an unknown error. Get help with
this error"

I also tried to install several updates from the Download Center. When I
click on the Download button, another window pops up with the following error:
"Internet Explorer cannot display the webpage

What you can try:
Diagnose Connection Problems

More information

"

I would appreciate it if you could help me.

Here's my PC information:
OS: Windows Vista Home Premium (6.0, Build 6001)
BIOS: Phoenix - AwardBIOS v6.00PG
Processor: AMD Athlon 64 X2 Dual Core Processor 5000+, 2.6GHz
Memory: 3582MB
DirectX Version: DirectX 10