Computer going crazy. HELP

Was lucky to even make it this far.
Internet has been giving a lot of page cannot be found etc. I've cleaned everything off using 3 different programs and manualy deleting. Still not working. Also noticed the proccessor speed had dropped nearly 800 mghz
Went into the bios and fixed that. But internets still messed up and now some programs will not open...Claims their is not enough ram. with 512mb i dought it. No viruses were detected. Hardly any addware or spyware. What the hell could be causing this
Now i just hope it will let me back to check replies
Internet has been giving a lot of page cannot be found etc. I've cleaned everything off using 3 different programs and manualy deleting. Still not working. Also noticed the proccessor speed had dropped nearly 800 mghz


Now i just hope it will let me back to check replies
