I want to restore my Compaq Presario 900 to factory settings

this link should help you out.
Compaq Presario Desktop to Factory Google Search

Why not remove the virus with your up-to-date Anti Virus software? Or you freeware MALWAREBYTES at : http://www.filehippo.com/download_malwarebytes_anti_malware/ Run a FULL scan , delete ALL results, reboot. If you have a Factory Recovery Partition,You can find the Factory Recovery procedure: http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&taskId=115&prodSeriesId=242213&prodTypeId=321957&objectID=c00006110

To restore your Compaq Presario notebook to factory settings read the information from this link.

hi.
there are two ways to completely restore settings of a computer:
1- enter Bios of your notebook (by pressing "delete" repeatedly") and select restore to manufacturer's settings.(or load from manufacture settings). THIS CAN RESTORE SETTINGS OF YOUR HARDWARE.

2- for restoring settings of Windows:
restart your notebook and before windows starts up (showing "windows starting") press F8 repeatedly.
then choose "load from last good configuration".

If u Create a restoring poit & use a original copy operating System then u restore it nahi to operating system repair kar le.
if u want to restore ur BIOS then open ur Bios from F2 & Load its default settings by its given instruction.............

try this first:

start menu,
all programs
accessories
system tools,
system restore
If it is not there, then you probably can not do it.

or

Try useing the F11 keys @ boot up, the restore to factory settings are there.

When you purchased the computer, you should have received a set of "System Restore" CD-ROMs. Use them.

If you have lost them, telephone HP/COMPAQ, and order a replacement set of "System Restore" CD-ROMs. The cost could be $20 for the set, and $20 for courier-shipping. When the disks arrive, use them.

P.S. Backup all your music/files/bookmarks/contacts before doing the "factory" reset.

Compaq/HP: When you first turn on the laptop and see the Compaq/HP logo screen, press the F11 key (you need to do this before the Compaq/HP logo disappears).

pls rate well

use recovery disk that came with computer

http://h10032.www1.hp.com/ctg/Manual/c00444244.pdf


this doc may help u ...