Physical Memory High, System Slow

On startup with nothing running but background programs, everything's normal usage via Task Mgr. Within 5 minutes, without starting any apps, the usage shoots up to at lest 2GB to 2.* GB (my total is 3GB) and stays there until I shut down. My cpu usage is erratic jumping from 40 to 90%, again with nothing running that I can tell. Looking at my Processes major memory users shows a few using between 6 & 4 MB, nothing to account for. I've tried running MS FixIt and msconfig stopping all non essential services and startups. This problem started yesterday, before that all was well, so I did a system restore to back 3 weeks ago, prior to Win. update, same thing. The only thing that I had done out of the ordinary was to use MS Media Center to record a 1 hr. TV show. I even deleted the show and turned off the Media Center Service, still no change. At times the CPU drops to normal and even one and awhile so does the RAM, but jumps back high on it's own.
Computer= Toshiba Notebook Model PSK2LU-001003, 3GB RAM
OS= Win 7
The unit is not usable in this state. HELP!

 

Hi my friend , what is the free capacity of your hdd ? You can run this

http://www.majorgeeks.com/files/details/superantispyware_free.html

you can also run this on line antivirus

http://forums.majorgeeks.com/showthread.php?t=149856

even go to Start - Run msconfig - ok , you have to push Disable all from Startup tab pushing Apply - ok , windows is asking you about restart - go for it :wave

 

Sorry for delay in responding, been working issue as time allowed. I tried your suggestions and some others. I have pinpointed the cause but not the cure. The cause is Microsoft Media Player, if disabled my sudden large memory usage disappears, or if I disable my wireless connection with Media Player working, no problem. Searching the Internet for cause and cure it would seem my MP is possibly trying to download things, as if the media sharing function is active. I don't ever download music or video, I've tried to identify a "sharing" function in MP or Media Central and can not. I have tried to follow Internet instructions from MS and other forums, my Win 7 doesn't seem to have the same files or something. I'm not sure turning sharing off (if it is on) will fix the problem. I do know the problem is within Media Player / Media Center, I can only use that computer with those services turned off. Since I would like to use this function to record TV, I would appreciate help and direction.