Same prob

You should try an online scan like Microsoft's http://www.microsoft.com/protect/products/computer/safetyscanner.mspx Even if it will tell you what the virus is then you can download a fix from http://www.symantec.com/business/security_response/removaltools.jsp to fix it.

Hello

The system idle process will always run at 99% but it will not actually use and system memory.

I recommend using AVG 8.5 and SuperAntiSpyware from SuperAntiSpyware.com

** Make sure that you remove any AV/ Firewalls or other spyware software before installing new software

I deal with these problems on a daily basis for my company. Install Malware Bytes, the free version works perfect. (Http://www.malwarebytes.org) Update the scanner (definitions file, just select the update tab) and run a full scan. Malware bytes will kill anything you have that you shouldn't have. Reboot, run again. It finds everything for me that AVG misses everytime.

Anti malware and anti spyware programs are not Anti-Virus. Your first line of defense, aside from a functioning firewall, should be a good antivirus. If you are using AVG because it's free, I can recommend both Avira & Avast, and if you are particularly concerned about system resource use, Eset NOD 32 is known to be lighter on use of resouces. Both MBAM & Spybot are great programs, but you need to have an anti-virus updated and running to protect yourself.
Regarding system idle process, this indicates that your CPU has nothing else to do...
" The System Idle Process Processors never rest. Once powered up, they must always be executing some thread of instructions. When not executing the thread of an active user or system process, they execute a thread of a process called System Idle Process. The System Idle Process has one thread per processor. It has such a low base priority that it runs only when nothing else is scheduled to run. This process does nothing but occupy the processors until a real thread is ready to use them. On a quiet machine, when you would expect processor use to be very low, the System Idle Process will be using most of the processor time."
I'm not sure what your original question or problem was, but if you are still struggling with it please write back with a comment to this same post.

I hope this information allows you to resolve this issue. If you need further assistance, please post back with a comment to this thread. If I've managed to answer your question or solve a problem, please take a moment to kindly rate this post....thanks!