Windows 7: Massive Memory Usage & Explorer Crashing

I've been having major problems with svchost.exe.. From what I can gather, this process relates to Windows update service; and I don't want to end the wrong process (since each leads to one or more separate locations) I would like to know what I can do to remedy this; because it is extremely irritating!

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I am also having trouble with Explorer crashing, which of course bombs my desktop.. I've been experienceing missing paths for icons, even the parent location of an executable program shows the standard 'file' image

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The latter of those two is the containing folder for that program of course; and the .ico is related to the file within it's properties, but does not show on the desktop or explorer window! )

Any help appreciated!

What's the problem with svchost.exe?

I did a quick bit of arithmetic and it looks like it's using about 120 MB of RAM.

If you have 4 GB of RAM, that would be about 3% of what you have.

If you have 8 GB of RAM, that would be about 1.5% of what you have.