What is a Computer Virus

[Caribeing]

What exactly is a computer virus, how do you know if your computer has one and how do you "cure" it. I have asked for help with this problem before but still unable to solve it. I have an Acer Laptop Vista, it keeps asking me to insert password. When I turn on my computer I put in my password, get to desktop and continue to work etc, then it goes back to password,I have tried system restore but to no avail , not technically minded, do you think I can solve this myself or do I need "professional" assistance

[pug100]

Some of your answers are here

http://en.wikipedia.org/wiki/Computer_virus

To cure a virus install and run a virus checker such as AVG.

http://free.grisoft.com/

Which is free.

[Mac70]

There is such a big variety of malicious software, viruses, rootkits, backdoors, downloaders, adware, foistware, rogue programs... the list goes on.
It would be impossible to know what your problem is by the description above.
You do have two options, really. You can pay for a technician to look it over, though he would most likely tell you reinstall Vista, or you can get free help at any one of many security forums online.
Many of those forums also have technical rooms, so if it isnt a malware problem you can simply move to another room for a technical expert to assist you, also for free.

[tommy39]

try this it.s a online scan from norton .it won't cure it but it will tell you what you have on the pc . it also takes a while, it is very comprehensive
http://security.symantec.com/sscv6/default.asp ?langid=ie&venid=sym