Laptop not showing desktop just remains blank when switched on

Whichf HP laptop? Is your PC hung up? What version of Windows?
Usually you can do a CTRL-ALT-DELETE and this brings up the Task manager. If your keyboard has a proper driver loaded, it will show you the Task manager screen. Select - start task manager. then look at the list of Processes. There should be atleast 9 processes running. Sometimes a virus in your system can lock your keyboard just to irritate you.

is your base unit still working when screen remain blank? if so it is related to video. consult a good laptop technician near you.

A white blank screen? That sounds like the virus changed your display settings. Click Ctrl+Alt+Del to get to the task manager. Press and hold the Ctrl key plus the Alt Key then hit the Del key. When the task manager opens up Click File at the upper left corner of the window then select New Task RUN. When the create New Task Window opens type: explorer.exe and hit OK. See if it starts populating your desktop icons and shows the start menu and task bar. If so, the virus changed your settings.

To change your display background click Start/Control Panel and look for Display or Appearance and Personalization. When it opens select the Desktop tab and change the desktop background. Hopefully the white will go away.

You may have to get into Safe Mode to do the above if the virus disabled the Task Manager.

reboot it in safe mode and if it shows desktop restart once again
booting in safemode hold F8 while restarting your machine choose start window in safe mode and hit enter
best of luck
if problem wont solve let me know please i will tell you another way

This almost sounds like the display setting on your laptop was changed to an external device. Most laptops are designed to be hooked up to an external display, such as a monitor or projector, specifically for presentations. You can alternate the display options in the following ways:

1. Laptop display only
2. External display only
3. Laptop+External clone
4. Laptop display + extended desktop on external display (dual monitor setup)

Check your laptop display settings and make sure that it's not in presentation mode (options 2-4) before connecting the KVM switch to it. It may be recognizing the KVM switch as an external display in option 4 mode.

simplest solution is start task manager by pressing ctrl alt and del simultaneously after task manager appears start file -new task from that type explorer and then there it is the problem is solved

Bring up task manager (Ctrl+Alt+Delete)
click applications tab
click new task
type in explorer.exe then click okay
If it boots up go to www.malwarebytes.org and download the free version. Install, update, and run a full scan.
Delete anything it finds.
Sometimes this works, sometimes it doesn't.
Good luck

You would be well advised to hit F8 and do a safe mode. Then check the disk. More details here: http://annoyances-resolved.blogspot.com/2009/09/laptop-wont-boot-and-shows-blank-screen.html

press ctrl+alt+del, task manager will show up,new task,run,type "explorer" without quotation,press enter

Try doing a control+alt+del and the selecting New Task then type explorer. This should bring up your normal windows desktop and icons, etc.