Microsoft (MSFT) has extended the end date by which OEMs can build and sell new Windows 7 Professional-equipped PCs but has not softened the standing Oct. 31 hard stop for the consumer version of the operating system.

The move is an interesting one particularly in light of some vendors such as Hewlett-Packard (HPQ) hawking their Windows 7-based PCs at promotional prices in campaigns to up disobliging PC sales. Last month, HP began offering customers up to $150 off for ordering desktops and laptops equipped with Windows 7, as the first PC manufacturer to overtly promote Windows 7 over Windows 8.

According to Microsoft’s Windows lifestyle fact sheet, updated as of Feb. 14, the vendor hasn’t established an end of sales date for Windows 7 Professional, or the date when a particular version of Windows no longer is shipped to OEMs or retailers. The Windows 7 Home end of sales date is Oct. 31. Both operating systems stopped selling at retail Oct. 31, 2013.

Microsoft’s end of support dates for Windows 7 haven’t changed, set at Jan. 13, 2015, for mainstream support and Jan. 14, 2020, for extended support. After the latter date, the vendor will not supply updates, security patches or fixes for any version of Windows 7.

The question remains, of course, What happens to Windows 7 Professional support if Microsoft ends its extended coverage of the OS on Jan. 13, 2015, as planned but still allows OEMs to pre-install the software on machines for sale?

A ZDNet report addressed that very issue to Microsoft and was told that OEMs typically “offer free warranty support for a period of time (usually one year) defined by the OEM. Because of this, there is a relatively small difference between mainstream support and extended support in the case of the OEM license because the OEM licensed versions of Windows continue to receive support directly from the OEM for the hardware and software.”

ZDNet also reported that the pre-installed end of sales date for Windows 7 Professional isn’t tied to the impending end of support date for Windows XP coming up April 8 or the slow uptake of Windows 8 thus far by the business community. Shad Larsen, Windows business planning team senior business program manager, said Windows 7 still commands the largest segment of Microsoft’s OS installed base and the vendor has no plans to walk away from it anytime soon, according to the report.