Reports from the NextCentury Web Portal download as CSV (comma-separated values) files, which open in spreadsheet programs such as Microsoft Excel.
When Excel opens a CSV file, it guesses what kind of data each column holds. Some serial numbers look like scientific notation to it, so it changes them: 70143E7 becomes 7.01E+11, and the original serial number is lost. Just opening the file is enough to change it, and the changed file can then fail to upload to another system.
To keep serial numbers as they are, import the file into Excel as text instead of opening it.
Import a report into Excel
In a new Excel sheet, open the File menu and select Import.
Select Text file, even though the report is a CSV, then select Import.
Choose the report file, for example in your Downloads folder, and select Get Data.
Make sure Delimited is selected, leave the other settings as they are, and select Next.
Under Delimiters, check only Comma, then select Next.
Select all the columns, choose Text as the column data format, then select Finish.
Choose where to put the data. In a new sheet, leave the default and select OK.
The report opens with every value exactly as it was in the file.
Save it as a CSV again
If you change the report and need to upload it to another system, save it as a CSV first: select File > Save As and choose CSV as the file format.