installed vista home basic and at startup computer shuts down

pls can someone assist me i installed windows home basic 32bit in a cpu that has 1ram and also 300 seagate hard drive and it was working fine with xp but when i upgraded it to vista home installed and came to start menu but then when i tried to clink on something it just froze and shut off and now when i power it up it goes to the lil loading bar to vista and then after like 2 min just shuts down and does nothing else .

Try Re-installing Vista, and reloading drivers. You may have hardware/driver incompatibility.
http://www.vistax64.com/tutorials/68767-clean-install-upgrade-vista.html