NEC Corp has decided to give local retail customers the option of having the Japanese version of the freeware Turbo Linux 4.0 operating system installed on PCs as an alternative to Windows 98. A NEC official said that use of the Unix-based Linux is increasing at universities and corporations. However, he said that it has been slow to catch on with home users because it is relatively difficult to use, but recent improvements in the user interface have made it more user-friendly. He said add-on modules have made it easier to use and applications suited to personal use are coming onto the market. From Friday NEC Personal Systems Ltd and 10 major retailers will offer Linux installation on NEC computers sold since May at a cost of about 23,000 yen ($190).