Why this error happend? nodejs Error: write EIO

I made a webApp with nodejs + mongodb + Backbone on window7-32bit, everything goes fine until yestoday. but I got this error this morning:

events.js:72
        throw er; // Unhandled 'error' event
              ^
Error: write EIO
    at errnoException (net.js:883:11)
    at Object.afterWrite (net.js:700:19)

I googled around but no luck, I tried update node, and then got this error:

npm ERR! Error: write EIO
npm ERR!     at errnoException (net.js:883:11)
npm ERR!     at Object.afterWrite (net.js:700:19)
npm ERR! If you need help, you may report this log at:
npm ERR!     <http://github.com/isaacs/npm/issues>
npm ERR! or email it to:
npm ERR!     <npm-@googlegroups.com>

npm ERR! System Windows_NT 6.1.7601
npm ERR! command "C:\\Program Files\\nodejs\\\\node.exe" "C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "update"
npm ERR! cwd C:\work\selink
npm ERR! node -v v0.10.4
npm ERR! npm -v 1.2.18
npm ERR! syscall write
npm ERR! code EIO
npm ERR! errno EIO

why this error happened suddenly? any hint about it?

Thanks for any ideas.