Click on the first cell to remove the gridlines and drag the pointer to the last row and column to highlight all. Right click on the highlighted area. Click on Format Cells from the menu. Click on the Border tab. On presets click on the "None" icon. The selected gridlines will be removed.
J.
Cooler Master Elite 430
Asus P8Z68-V PRO/GEN3
Intel Core i5 2500K, 3.30 GHz
ADATA 8 GB DDR3
EVGA GTX 560 1GB PCIe
Sound Blaster Recon3D PCIe
1 TB Seagate Barracuda 7200 RPM
P/S: Corsair GS800
Windows 10 Pro 64 Bit
. . . by Digital Storm