Why can I not file as married filing separately as a widow? It continually asks for my deceased spouses information. I am not filing for him as he is deceased.

Sorry for your loss.  When did he die?  You can file a Joint return the year your spouse died.  For the next two years following a husband's or wife's death, the surviving spouse can file as a qualifying widow or widower if they have a qualifying child. That basically lets you continue to use the same tax brackets that apply to married-filing-jointly returns.  After the year of death if you don't have a child you file as Single.

Then to file Single you should start over and set up a new account for yourself and not transfer from last year.  You will have to re enter any prior carryovers and depreciation, etc. manually.

How to start another return in the Online version  

https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-start-another-return-in-turbotax-online/00/25596

In your case, as VolvoGirl mentioned, the year that your husband passed affects how you should file your return.  You have some options on what filing status to use.  

• If your spouse was still alive as of December 31, 2023, you can file your 2023 return jointly with your late spouse.
• If your spouse died in 2023, you can file jointly with your late spouse unless you remarried in 2023.
  • In that case, you can file a joint return with your new spouse and file your deceased spouse's return as Married Filing Separately.
• If your spouse died in 2021 or 2022, you didn't remarry in 2023, and you have a child that meets certain qualifications, you might be able to file as a Qualifying Surviving Spouse, which has certain tax advantages.  When you go through the Personal Info section in TurboTax, we'll determine if you meet those requirements. 
  • If you do not have a child, and you did not remarry then your filing status should be Single. 

@mickierigsby1951  

No one seems to have answered the question which is, "why can I not file married filing separate..."?

The answer is, you can file married separate if you wish. However, the IRS requires certain information about the other spouse. That information is required.

You do not want to file separately if you can avoid it. Filing separately loses you access to a number of credits.

The IRS says on page 22 in Pub 17, 

"Spouse died during the year. If your spouse died during the year, you are considered married for the whole year for filing status purposes. If you didn't remarry before the end of the tax year, you can file a joint return for yourself and your deceased spouse. For the next 2 years, you may be entitled to the special benefits described later under Qualifying Surviving Spouse."