Question : error writing to memory.

I have a persistant problem on my brothers computer. Every time I try to run anything with an exe extension it fails with an error message that says it couldn't write the data. With msn messenger and yahoo I get the typical this program could not launch do you want to send an error report to microsoft. But I get similar messages with lots (but not all) things I try to run including games..

Ive scanned with nod32 antivirus , spybot search and destroy and lavasoft adaware.  Also performed a registry scan with the "complete maintainance" in tuneuputilities.  Which found multiple errors and succesfully  fixed them but the problem persists.

Seeing as the error mentions something about being unable to write data I even checked to see if any folder was set to read only and unchecked it. Even that hasn't worked. So what could the problem be here? I an contemplating some sort of application to flush the memory from my ram, maybe theres some sort of corrupt data problem in there, but ive forgotten what i need to do that. Suppose the ram could always be faulty though or the hard disk?

If anyone can help me with this I would greatly appreciate it. I am far from unexperienced with computers but this one has me stumped. .

Answer : error writing to memory.

If possible Connect this Desktop Hard=Disk Drive to another machine as a slave that machine should be clean and properly updated antivirus so scan throughly with Antivirus & spybot so it removes the virses and spywares and also run chkdsk /r command and then if not solved with this you have to reinstall the operating system with Repair option.

Regards,
VIjay Kadadi