Radio button 
Ragged 
Ragged left 
Ragged right 
RAID 
RAM 
RAM cache 
Random access memory 
Range left 
Ray tracing 
Read only 
Read only attribute 
Read only memory 
Real memory 
Real mode 
Real time 
Real-time animation 
Re-boot 
Record or write head 
Recycle Bin 
Red, green, blue (RGB) 
Reduced instruction set computer (RISC) 
Refresh 
Refresh rate 
Region fill 
Registry 
Re-hyphenation 
Relational database 
Release 
Remote access 
Renaming 
Rendering 
Repetitive strain injury (RSI) 
Replay 
Resample 
Reset 
Resolution 
Resource 
Resource sharing 
Reverse characters 
Reverse video 
RGB 
RGB monitor 
Ribbon cable 
Rich text format (RTF) 
Right justify 
Right-click menu 
Right-hand button 
RISC 
ROM cartridge 
Root directory 
Row 
RSI 
Ruler line 
Runaround 
Run command 
Run time