"Low on memory" message

I keep getting this message and my computer has been sluggish. I've done virus and adware scans and everything seems fine. A look at my performance screen indicates that I have plenty of memory (screen shot attached,) though I don't know what "cached" "available" and "free" mean. The "free" memory seems like it may be low. I've seen it drop to 20 MB. I have 4G of RAM on the way and will install that, but the 2G I already have is more RAM than any computer I've owned in the past and I'm running all the same programs I did on those. Am I overlooking something?

First, I would try a Clean Boot to see if it helps.

https://www.sevenforums.com/tutorials/179159-troubleshoot-application-conflicts-performing-clean-startup.html

Adding more Ram is certainly a good idea.

After you Clean Boot check Tack Manager again to see how much memory is being used.

Keep us posted,

John

There is nothing unusual in the screenshot. The "free" value should be low, zero being the optimum value. Low memory errors usually have nothing to do with a shortage of RAM. More likely it is due to the commit charge hitting the commit limit. But that isn't even close in the screenshot.

Whatever is causing the problem is not shown in Task Manager. Such problems can be very transient in nature.