sims 3 crashing as soon as I load up a household.

AlexJH14_  Windowed mode shouldn't have anything to do with this.  If the game is crashing, there should be a crash dump.  But perhaps something else is crashing instead and taking Sims 3 down with it.  There isn't anything at all from around that time in the Reliability Monitor?  If not, we'll need to look for information some other way.

First, look for a Sims 3-related crash.  Click Windows key-R and copy and paste this:

%LocalAppData%\CrashDumps

When you enter, you'll see a list of .dmp files.  If one of them is from Sims 3 or the EA App, please upload it to a third-party filehosting site (Google Drive, Dropbox, etc.) and link it here.  If you see a crash dump that was written at exactly the time the game crashed, I'd like that too.  But in either case, please only upload files from after we started troubleshooting here.

If there is no Sims 3 .dmp file, you can enable them:

• Hit the Windows key, type "command prompt" in the box, right-click on Command Prompt in the search results, and select Run as Administrator
• In the window, paste "reg add "HKLM\Software\Microsoft\Windows\Windows Error Reporting\LocalDumps\devenv.exe" /v DumpType /d 2 /t REG_DWORD" without the outside quotes into the box, and enter
• Launch Sims 3 and wait for it to crash (whether you can play at all or not)
• After it crashes, wait for any crash dialogs to finish
• Then hit Windows key-R and paste "%LOCALAPPDATA%\CrashDumps" without quotes into the box, and enter
• Upload the last .dmp file to a free filesharing site and link it here
• When you want to undo the auto crash log dumps, open Command Prompt as before, paste "reg delete "HKLM\Software\Microsoft\Windows\Windows Error Reporting\LocalDumps" /f" without the outside quotes, and enter.

If nothing turns up even after this, look for a corresponding file in C:\Windows\Minidump, and if you find one, upload it as described above.  You'll need to copy the file where it is and paste it onto your desktop before you can do anything else with it, as this is a protected folder.