Assuming that the box responds to pings and you have a logon to the box with root or sudo credentials....
Log into the box (assuming it's a text console, if not open up a terminal (command prompt) and type:
If you get a few lines with the word "squid" in them, squid is running, so try to access the internet from the console using a text-mode browser, popular ones that may be installed are w3m, lynx or links
Code:
w3m http://www.google.co.uk
If you don't see a few lines with "squid" in them when your run ps -A | grep squid on the console type:
which will tell you where squid is installed - type in :
Code:
/fully/qualified/path/to/squid
using root credentials
or use
Code:
sudo /fully/qualified/path/to/squid
To start squid. If squid is broken it should tell you straightaway, if it breaks in a short time it should squawk and die, dumping error messages to the console.
You could also look in the logs at:
/var/log/squid/
/var/log/syslog
/var/log/messages
to see if any of them mention problems.
To stop this become a massive if/then post, tell us what you find re squid working or not, then we can make more suggestions.