I wonder if anyone can point me in the right direction. I have a workbook with 12 sheets, 1 for each month of the year. Each month has around 30,000 user IDs on it (this is a log of each time a user logs into our website).
What I need to do is find out how many unique users have logged into our site for the whole year, or in other words, remove duplicate user ids accross the workbook.
I realise that this will probably destroy my processor, so was wondering the best way to do it?
I also have all this information in ONE spreadsheet if it would be easier? I just copied and pasted each month into a column (Jan is column A, feb in B, mar in C etc)
I ran some code on this sheet to remove dupllicates from column A:E but this was taking AGES!
Thanks in advance for any help