Guyz i just discovered that my system is going nuts.
It was performing very fine in the afternoon when i used it to back up my phone ie sony ericsson p1i, at night when i wanted to use, after booting, when i click on an icon, it will show loading sign and will never load but if i continously click on the icon a message comes on showing ''windows explorer not responding'' with other options like 'close windows etc' i dont really know if it is a problem i can fic or should i ask for a technicians help.
The system's configuration is compaq v4000 upgraded from windows xp home to windows vista ultimate. It was built for xp but still vista capable cos its written on it. It has 512 mb RAM, 80gb hdd

But my guy u sef follow dey kill the system,how can you use 512MB for Windows Vista Ultimate?You need to up your RAM to 2GB!As for the issue it could be a virus.Which Antivirus program do you have installed?

I just brought the system back from where the upgrade was done and am about installing an avast antivirus before it happened, if its virus what do i do cos i have some important files in the system

If it is a virus,get a good antivirus like NOD32 or Kaspersky.Just google and download.