Startup does it have a virus

You might try going back into your setup and disabling Secure Boot, and look for "verbose" or "full" mode for startup - this will print the entire startup sequence on boot - valuable for troubleshooting hardware and some software issues.

As for the ability to boot to Safe Mode - the process is different for different OS - you can find detailed step for starting in Safe Mode in Win8/8.1 here
Windows Startup Settings including safe mode Windows Help

Restart your computer During the boot process you will see on the screen to press a certain key to enter setup usually the Delete or the F2 key Press and hold that key during the boot up process to enter BIOS the using arrow key scroll down to advanced bios features press enter change your first boot device to cd,press escape then press f10 to save to cmos to restart note this will erase you operating system you will have to have an operating system disk to load it onto you hard drive or create a partition to load another operating system (note after you have loaded the operating system you should go back and change the first boot device to your failsafe or optimized defaults) after windows has loaded your computer will automatically restart it might restart 2 times one to finish the installation the next will be because the operating system is loaded and will boot from your cd during the boot process you will see on the screen to press a certain key to enter setup Press and hold that key during the boot up process to enter BIOS using the arrow keys load failsafe defaults or load optimized defaults press escape then press f10 to save to cmos to restart otherwise it will keep booting from the cd /dvd drive
if its password protected (locked)

Restart your computer repeatedly tapping the f8 key to enter safe mode while the screen is black once in safe mode where the only things working will be your keyboard and mouse allowing you to attempt to repair your computer Windows Advanced Options Menu Please select an option: Safe Mode
Safe Mode with Networking
Safe Mode with Command Prompt Enable Boot Logging
Enable VGA mode
Last Known Good Configuration (your most recent settings that worked)
Directory Services Restore Mode (Windows domain controllers only)
Debugging Mode Start Windows Normally
Reboot
Return to OS Choices Menu Use the up and down arrow keys to move the highlight to your choice select safe mode with command prompt Click start run type cmd press Enter black screen should open DOS mode this will vary depending on your operating system type in net user username For eg. If you want to change administrator password , type net user Administrator It will prompt you to enter the new password. Enter the new password and the password is changed if this fails you will need to Select safe mode with networking to download you could download all of these or just one save them to a usb drive for later use if one fails to remove the password Windows Password Recovery Basic http://majorgeeks.com/CmosPwd_d239.html A CMOS BIOS password recovery tool Editors note: This tool should only be used by experienced computer users. Please see the enclosed read me if you would like to run it from Windows. Failure to follow instructions (from Windows) will cause your anti-virus to flag this as a virus. http://majorgeeks.com/Dr._Freeware_System_Utilities_d6416.html Dr.Freeware System Utilities which includes data recovery software, data backup, password reset tools for Windows helps you to maintain your system. Dr.Freeware is freeware, you can download and use it for free. Hope this helps.

Turn on the computer and begin hitting the "F8" key when you see the BIOS screen.

This will take you to the Safe Mode menu.

Use the arrow keys to highlight "Safe Mode," then hit "Enter" on your keyboard.

This will boot your computer in Safe Mode, a minimalist manner of operating Windows that runs only essential Windows files.

If using Windows XP in Safe Mode, click the "Start" button and then click "Run." In the box that pops up, type "msconfig" and hit "Enter."

If using Windows Vista or Windows 7, click the Windows logo in the bottom left corner of the screen, type "msconfig" in the search field and then hit "Enter."

This will open the System Configuration Utility.

In the System Configuration Utility box, click the "Services" tab, check the box that reads, "Hide All Microsoft Services," click "Disable All" and then click "Apply."

In the System Configuration Utility box, click the "Startup" tab, click "Disable All" and then click "Apply." Next, click the "Close" box.

A box will pop up that prompts you to restart your computer.

Select "Restart" and let the computer restart itself, allowing it to boot to Windows normally.

If the computer still stalls when trying to boot to Windows, restart the computer and boot to Safe Mode again.

Run your antivirus program in Safe Mode, deleting any files that are flagged as viruses, spyware or malware. Restart the computer and boot to Windows normally

hope this helps

Turn on the computer and begin hitting the "F8" key when you see the BIOS screen.

This will take you to the Safe Mode menu.

Use the arrow keys to highlight "Safe Mode," then hit "Enter" on your keyboard.

This will boot your computer in Safe Mode, a minimalist manner of operating Windows that runs only essential Windows files.

If using Windows XP in Safe Mode, click the "Start" button and then click "Run." In the box that pops up, type "msconfig" and hit "Enter."

If using Windows Vista or Windows 7, click the Windows logo in the bottom left corner of the screen, type "msconfig" in the search field and then hit "Enter."

This will open the System Configuration Utility.

In the System Configuration Utility box, click the "Services" tab, check the box that reads, "Hide All Microsoft Services," click "Disable All" and then click "Apply."

In the System Configuration Utility box, click the "Startup" tab, click "Disable All" and then click "Apply." Next, click the "Close" box.

A box will pop up that prompts you to restart your computer.

Select "Restart" and let the computer restart itself, allowing it to boot to Windows normally.

If the computer still stalls when trying to boot to Windows, restart the computer and boot to Safe Mode again.

Run your antivirus program in Safe Mode, deleting any files that are flagged as viruses, spyware or malware. Restart the computer and boot to Windows normally

hope this helps

The error indicates that there's a hard drive issue. If it just happened after the hard disk is reinstalled, remove it and reinstall it. It could be a problem caused by loose connection or improper connections. If the same problem repeats, install the hard drive on another system (to verify whether it works on another machine or not and to confirm it still works). If it doesn't work on another computer/system then your only option to run the system is replacing the hard disk. If it works on another computer or if it's detected on another system, then there could be problem with the hard disk, eg. Corrupt Partition, Windows Corrupt etc....
First of all, try booting into Safe Mode. You have to press F8 during the startup to go into Advanced Boot Options. Once you are in the Windows Advanced Boot Options, select Safe Mode using the up and down arrow keys on your keyboard. If it still doesn't work, it's the hard disk issue. Try with another Hard Disk.
But if in case you can boot into safe mode, check the Hard Disk for errors. In other words, run Windows Checkdisk utility. Hope this helps.
Let me know if you need further help.
Good Luck.
Thanks for using FixYa.

if is not start in safe mode you must need to winxp recovery disk to repair windows xp.
Boot your computer with winxp disk then repair it.
Please let me know.

When the computer first boots up, press the F8 key when the eMachines logo is replaced by the first Microsoft screen, then select Safe Mode from the list. If the computer will not boot in Safe Mode, you will need to boot from your Windows CD and select the repair installation option. If you can boot in Safe Mode, you will need to find out what is causing the system to reboot during startup. With the msconfig utility, disable all unnecessary startup programs and services, then try restarting the computer normally. If this works, you need to use the msconfig utility to add the startup programs and services back one-by-one until it fails to boot again (to locate your troublemaker). Keep repeating this until all services and programs (except the one causing the problem) are back in the lineup.

Here are some steps to use MSCONFIG to force your computer into SAFE MODE

1. Click on Start and then Run.
   
2. In the text box in the Run window, type msconfig and click OK. This will open the System Configuration Utility program.
   Note: Do not make changes in the System Configuration Utility other than those outlined here to avoid causing serious system issues. This utility controls a number of startup activities other than those involved with Safe Mode.
   
3. Click on the BOOT.INI tab located at the top of the System Configuration Utility window.
   
4. Check the checkbox next to /SAFEBOOT and click OK.
   
5. You will then be prompted to either Restart, which will restart the PC immediately, or Exit Without Restart, which will close the window and allow you to restart the PC manually.
   
6. After the restart, the PC will automatically boot into Windows XP Safe Mode.
   Note: Windows XP will continue to boot into Safe Mode until the System Configuration Utility is configured to again boot normally.
   
7. When your work in Safe Mode is complete, click on Start and then Run. Type msconfig in the text box and click OK.
   This will again open the System Configuration Utility program.
   
8. Choose the Normal Startup radio button and click OK.
   
9. You will then be prompted to either Restart, which will restart the PC immediately, or Exit Without Restart, which will close the window and allow you to restart the PC manually.
   
10. After the restart, the PC will boot into Windows XP normally and will continue to do so.
    
    These instructions were written by About.com
    http://pcsupport.about.com/od/tipstricks/ht/smsysconfig.htm
    

if the system was able to enter the desktop and restarts...once possible cause is a virus...scan the pc via safemode or reinstall windows.

but if it didn't enter the OS desktop...cause might be the boot loader or MBR is damage..

worth a try:

Run the Recovery Console from the Windows XP startup disks or the Windows XP CD-ROM, follow these steps:
1. Insert the Windows XP startup disk into the floppy disk drive, or insert the Windows XP CD-ROM into the CD-ROM drive, and then restart the computer.

Click to select any options that are required to start the computer from the CD-ROM drive if you are prompted.
2. When the "Welcome to Setup" screen appears, press R to start the Recovery Console.
3. If you have a dual-boot or multiple-boot computer, select the installation that you must access from the Recovery Console.
4. When you are prompted, type the Administrator password. If the administrator password is blank, just press ENTER.
5. At the command prompt, type this commands one at a time.

FIXMBR C:
FIXBOOT C:
COPY [CDDRIVE]:\I386\NTLDR C:\
COPY [CDDRIVE]:\I386\NTDETECT.COM C:\
BOOTCFG /rebuild


6. To exit the Recovery Console and restart the computer, type exit at the command prompt, and then press ENTER.

http://support.microsoft.com/kb/262381/en-us

Restart in Safe Mode and Use Msconfig.exe loadTOCNode(2, 'resolution'); Restart your computer, press and hold down the CTRL key after your computer completes the Power On Self Test (POST), and then choose Safe Mode from the Startup menu. For additional information about Windows 98 startup, click the article number below to view the article in the Microsoft Knowledge Base: 178548 (http://support.microsoft.com/kb/178548/EN-US/) No 'Starting Windows 98' Message at Startup After your computer restarts in Safe mode, use the System Configuration Utility tool (Msconfig.exe) to minimize conflicts that may prevent your computer from finishing Setup.

To start and use the System Information tool: 1. Click Start, point to Programs, point to Accessories, point to System Tools, and then click System Information. 2. On the Tools menu, click System Configuration Utility. 3. On the General tab, click Selective Startup, and then click to clear the following check boxes: • Process Config.sys File • Process Autoexec.bat File • Process Winstart.bat File (if available) • Process System.ini File • Process Win.ini File • Load Startup Group Items