An external would not let you run Windows without way too much trouble and research.
If you pull the drive and put that into an external that's a good idea but I wonder why you would not have your documents up on a memory stick or DROPBOX in case of a virus?
--> Try this next to see if your files are there:
http://www.howtogeek.com/howto/windows-vista/use-ubuntu-live-cd-to-backup-files-from-your-dead-windows-computer/
I have a Compaq Presario V4000 XP home edition that has crashed. I have gone in and run some diagnostics and received the following info. The quick and comprehensive hard drive test gave the following results: Quick: pass
Comprehensive: #2 -07 FAIL
I also ran a different test yesterday and received the following:
Technical information:
STOP: 0x0000006F (0xC000000E, 0x00000000, 0x00000000, 0x00000000)
Is my harddrive shot? If so, is it worth purchasing an external harddrive. I purchased the Presario in 2005 for graduate school and have a fair number of documents I want to retrieve as well as photos.

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