You need to add "tblQuickFixEngineering.InstalledOn >= GetDate() - 7" to the where statement of your query.
I have altered the built-in report "Windows: installed Windows updates" to list only the assets on which a Windows update was installed during the last 7 days:
Select Top 1000000 tblAssets.AssetID,
tblAssets.AssetName,
tblAssets.Domain,
tblAssets.Username,
tblAssets.Userdomain,
Coalesce(tsysOS.Image, tsysAssetTypes.AssetTypeIcon10) As icon,
tblAssets.IPAddress,
tsysIPLocations.IPLocation,
tblAssetCustom.Manufacturer,
tblAssetCustom.Model,
tsysOS.OSname As OS,
tblAssets.SP,
tblAssets.Lastseen,
tblAssets.Lasttried,
tblQuickFixEngineeringUni.HotFixID,
tblQuickFixEngineeringUni.Description,
tblQuickFixEngineeringUni.FixComments,
tblQuickFixEngineeringInstalledBy.InstalledBy,
tblQuickFixEngineering.InstalledOn,
tblQuickFixEngineering.Lastchanged As LastChanged
From tblAssets
Inner Join tblAssetCustom On tblAssets.AssetID = tblAssetCustom.AssetID
Inner Join tsysAssetTypes On tsysAssetTypes.AssetType = tblAssets.Assettype
Inner Join tblState On tblState.State = tblAssetCustom.State
Inner Join tsysIPLocations On tsysIPLocations.LocationID =
tblAssets.LocationID
Inner Join tblQuickFixEngineering On tblQuickFixEngineering.AssetID =
tblAssets.AssetID
Inner Join tblQuickFixEngineeringUni On tblQuickFixEngineeringUni.QFEID =
tblQuickFixEngineering.QFEID
Left Join tblQuickFixEngineeringInstalledBy
On tblQuickFixEngineeringInstalledBy.InstalledByID =
tblQuickFixEngineering.InstalledByID
Left Join tsysOS On tsysOS.OScode = tblAssets.OScode
Where tblQuickFixEngineering.InstalledOn >= GetDate() - 7 And
tblState.Statename = 'Active'
Order By tblAssets.Domain,
tblAssets.AssetName,
tblQuickFixEngineeringUni.HotFixID