What? Errcode: 22

I just started adding categories and was able to create two, then on the thrid try I received this error:

1 Can't create/write to file ' c:\php#sql_e24_0.MYI' (Errcode: 22)
in:
[select c.categories_id, cd.categories_name, cd.categories_description, c.categories_image, c.parent_id, c.sort_order, c.date_added, c.last_modified, c.categories_status from categories c, categories_description cd where c.parent_id = '0' and c.categories_id = cd.categories_id and cd.language_id = '1' order by c.sort_order, cd.categories_name]
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Any idea what this means?!?! I've installed and customized over 10 ZenCart's and have never seen this before. What did I do?!!??