There are two possible reasons why this size changing happens:
1. Enlarged Screen Fonts
User A is using standard font sizes (100%). User B has adjusted enlarged screen fonts (e.g. 125%). User A saves the Excel sheet with the bar codes in normal (correct) size. User B opens the sheet and discovers the bar code object with a different size (scaled according to the difference in screen font sizes).
Excel scales the bar code objects independently from TBarCode Office. The only solution would be to use the same readability options (screen font enlargement) on all involved PCs.
2. Different Screen Resolution
User A has a screen resolution of 1280x1024 Pixels. User B has a screen resolution of 1600 x 1200 Pixels. User A saves the Excel sheet with a bar code in normal (correct) size. User B opens the sheet and discovers the bar code object with a different size (scaled according to the difference in screen resolution between A and B).
Excel scales the bar code objects independently from TBarCode Office. The only solution would be to use the same screen resolution on all involved PCs.