Under hp update checking critcal errors, app tried to reinstall to correct the problem, but couldn't

Question

CompaqPresarioPC AY028AA-ABA
WINDOWS 7
EVENT ISSUES: WELL THERE'S 34,000 CRITICAL ERRORS ON MY COMPUTOR.
I  went to hp update, they identified the problem with the critical errors WINDOWS INSTALLER SERVICE is not correctly installed. contact SUPPORT PERSONNEL...so hp could not fix my problem
all I have on my computor is my printer, and webcam. I don't have any upgrades to the system itself.
My COMPAQPresarioPC  model #;  CQ5300Y
                                           product #;  AY028AA-ABA
                                              serial #;  [Personal Information Removed]
                              software build #;   A1NAv6PrA3
                                     service ID #;   070-410
                                         PCBrand ;   Presario

Answer 1

Hello candace1986,
Let's see if we can get the Windows Installer up and running for you. Try these steps
Method 1: 
Start the Windows Installer service 
1. Click Start, type Services.msc and press {ENTER} 
2. Double-click Windows Installer 
3. Set the Startup type of Windows Installer to Manual 
4. Click Start to start the service. Note down the error message if any. 
5. Click OK. 
Method 2:
Unregister and re-register the Windows Installer to do that follow the steps provided below. 
1. Click Start, click Run, type MSIEXEC /UNREGISTER, and then click OK. Even if you 
do this correctly, it may look like nothing occurs. 
2. Click Start, click Run, type MSIEXEC /REGSERVER, and then click OK. Even if you 
do this correctly, it may look like nothing occurs, or you may briefly see an hourglass. 
After you run this command, the operation is complete. 
3. Try your Windows Installer-based application again. 
Method 3:
Try performing SFC scan on the computer. 
1. Click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator. If you are prompted for an administrator password or for a confirmation, type the password, or click Allow 
2. Type the following command, and then press ENTER: sfc /scannow 
[The sfc /scannow command scans all protected system files and replaces incorrect versions with correct Microsoft versions.] 
A message will appear stating that 'The system scan will begin'. Be patient because the scan may take some time 
3. If any files require a replace SFC will replace them. You may be asked to insert your Win7 DVD for this process to continue 
4. If everything is okay you should, after the scan, see the following message "Windows resource protection did not find any integrity violations" 
5. After the scan has completed, close the command prompt window, restart the computer and check. 
Check the below mentioned link for further guidance on SFC scan – 
Source: Windows installer is not correctly installed windows 7
Let me know the results after you have completed them. If method 1 works then there is no need to continue same as if method 2  works.
Please post back your results.
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