Many people have been having issues with Excel deleting the leading zero from a column and then when they import their edited product file to ProStores the items get messed up.
Well there is a solution!
Fresh from the ProStores Message Boards. http://discussionboard.prostores.com/showpost.php?p=40709&postcount=13
1. Open a new document in Excel.
2. Go to Data > Import External Data > Import Data…
3. Browse to your csv file.
4. This should load the Text Import Wizard.
5. Click Next.
6. Select Comma as the Delimiter (unslect Tab if it’s selected).
7. Click Next. This is where you can define the format of each of the columns. In your case, you would select the SKU column and then select Text as the format.
8. Continue and finish the wizard.
Make sure to save the file as a csv when you’re done.
Keep in mind that this only works as you’re working in Excel. Meaning, if you you close the file and then re-open it, Excel will try to interpret that value as a number and strip the leading zeros again. You’ll have to import the file as described in the steps above in order for it to retain the Text format.