A lot of microsoft hidden files have the ability to send information back to microsoft and it is the same with other kinds of programs such as ICQ and yahoo messenger. Some cookies as well as adware programs also do this. You don't have to turn them on, but the minute they detect a network connection, they will attempt to send data and then receive data again.
Use a firewall program (Syquest is not bad and freeware) and it will tell you what is trying to access the internet, it will also ask if you would want to block it. Programs like norton also schedule their liveupdates to run automatically and in the background.
An example is when using XP, the msn explorer and windows messenger will always attempt to access the internet to look for updates. this would entail sending information about your computer to the updates server and if you allowed the programs to automatically update then they will do this in the background.
The other thing is a virus/worm... this one is easy, run a virus fix (if you know which worn) http://www.symantec.com or scan your comp with a virus scanner program and see what you come up with.
yup..sends out data the minute i log on..any preventive or precautionary measures i should take?
This will bring up a list of active connections. If your system is not doing anything, you shd not be seeing the "Established" connection with an IP pegged to it.
If the IP is not familiar, ie not from your ISP, goto www.samspade.org, key in the IP address and click on do stuff. This will perform a traceroute for you and you should be able to establish where this IP came from. Samspade is very good as it is able to perform a DNS resolution for you......ie, if there are certain sites which you cannot access due to some proxy problems, you can convert the DNS into an IP and key this into your URL address.
If the source comes from somewhere else other than your ISP, ICQ, Yahoo messenger, MSN, etc, better get yourself some programs like ZoneAlarm, Tiny Firewall, Ad-Aware, etc from www.download.com